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 make_request_fn 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_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 708         if (IS_ERR(rq))
 709                 return PTR_ERR(rq);
 710
 711         if (cgc->buflen) {
 712                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 713                                       GFP_NOIO);
 714                 if (ret)
 715                         goto out;
 716         }
 717
 718         scsi_req(rq)->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 719         memcpy(scsi_req(rq)->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 720
 721         rq->timeout = 60*HZ;
 722         if (cgc->quiet)
 723                 rq->rq_flags |= RQF_QUIET;
 724
 725         blk_execute_rq(rq->q, 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                 generic_make_request(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 /*
1086  * recover a failed write, query for relocation if possible
1087  *
1088  * returns 1 if recovery is possible, or 0 if not
1089  *
1090  */
1091 static int pkt_start_recovery(struct packet_data *pkt)
1092 {
1093         /*
1094          * FIXME. We need help from the file system to implement
1095          * recovery handling.
1096          */
1097         return 0;
1098 #if 0
1099         struct request *rq = pkt->rq;
1100         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1101         struct block_device *pkt_bdev;
1102         struct super_block *sb = NULL;
1103         unsigned long old_block, new_block;
1104         sector_t new_sector;
1105
1106         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1107         if (pkt_bdev) {
1108                 sb = get_super(pkt_bdev);
1109                 bdput(pkt_bdev);
1110         }
1111
1112         if (!sb)
1113                 return 0;
1114
1115         if (!sb->s_op->relocate_blocks)
1116                 goto out;
1117
1118         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1119         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1120                 goto out;
1121
1122         new_sector = new_block * (CD_FRAMESIZE >> 9);
1123         pkt->sector = new_sector;
1124
1125         bio_reset(pkt->bio);
1126         bio_set_dev(pkt->bio, pd->bdev);
1127         bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0);
1128         pkt->bio->bi_iter.bi_sector = new_sector;
1129         pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1130         pkt->bio->bi_vcnt = pkt->frames;
1131
1132         pkt->bio->bi_end_io = pkt_end_io_packet_write;
1133         pkt->bio->bi_private = pkt;
1134
1135         drop_super(sb);
1136         return 1;
1137
1138 out:
1139         drop_super(sb);
1140         return 0;
1141 #endif
1142 }
1143
1144 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1145 {
1146 #if PACKET_DEBUG > 1
1147         static const char *state_name[] = {
1148                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1149         };
1150         enum packet_data_state old_state = pkt->state;
1151         pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1152                 pkt->id, (unsigned long long)pkt->sector,
1153                 state_name[old_state], state_name[state]);
1154 #endif
1155         pkt->state = state;
1156 }
1157
1158 /*
1159  * Scan the work queue to see if we can start a new packet.
1160  * returns non-zero if any work was done.
1161  */
1162 static int pkt_handle_queue(struct pktcdvd_device *pd)
1163 {
1164         struct packet_data *pkt, *p;
1165         struct bio *bio = NULL;
1166         sector_t zone = 0; /* Suppress gcc warning */
1167         struct pkt_rb_node *node, *first_node;
1168         struct rb_node *n;
1169         int wakeup;
1170
1171         atomic_set(&pd->scan_queue, 0);
1172
1173         if (list_empty(&pd->cdrw.pkt_free_list)) {
1174                 pkt_dbg(2, pd, "no pkt\n");
1175                 return 0;
1176         }
1177
1178         /*
1179          * Try to find a zone we are not already working on.
1180          */
1181         spin_lock(&pd->lock);
1182         first_node = pkt_rbtree_find(pd, pd->current_sector);
1183         if (!first_node) {
1184                 n = rb_first(&pd->bio_queue);
1185                 if (n)
1186                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1187         }
1188         node = first_node;
1189         while (node) {
1190                 bio = node->bio;
1191                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1192                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1193                         if (p->sector == zone) {
1194                                 bio = NULL;
1195                                 goto try_next_bio;
1196                         }
1197                 }
1198                 break;
1199 try_next_bio:
1200                 node = pkt_rbtree_next(node);
1201                 if (!node) {
1202                         n = rb_first(&pd->bio_queue);
1203                         if (n)
1204                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1205                 }
1206                 if (node == first_node)
1207                         node = NULL;
1208         }
1209         spin_unlock(&pd->lock);
1210         if (!bio) {
1211                 pkt_dbg(2, pd, "no bio\n");
1212                 return 0;
1213         }
1214
1215         pkt = pkt_get_packet_data(pd, zone);
1216
1217         pd->current_sector = zone + pd->settings.size;
1218         pkt->sector = zone;
1219         BUG_ON(pkt->frames != pd->settings.size >> 2);
1220         pkt->write_size = 0;
1221
1222         /*
1223          * Scan work queue for bios in the same zone and link them
1224          * to this packet.
1225          */
1226         spin_lock(&pd->lock);
1227         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1228         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1229                 bio = node->bio;
1230                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1231                         get_zone(bio->bi_iter.bi_sector, pd));
1232                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1233                         break;
1234                 pkt_rbtree_erase(pd, node);
1235                 spin_lock(&pkt->lock);
1236                 bio_list_add(&pkt->orig_bios, bio);
1237                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1238                 spin_unlock(&pkt->lock);
1239         }
1240         /* check write congestion marks, and if bio_queue_size is
1241            below, wake up any waiters */
1242         wakeup = (pd->write_congestion_on > 0
1243                         && pd->bio_queue_size <= pd->write_congestion_off);
1244         spin_unlock(&pd->lock);
1245         if (wakeup) {
1246                 clear_bdi_congested(pd->disk->queue->backing_dev_info,
1247                                         BLK_RW_ASYNC);
1248         }
1249
1250         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1251         pkt_set_state(pkt, PACKET_WAITING_STATE);
1252         atomic_set(&pkt->run_sm, 1);
1253
1254         spin_lock(&pd->cdrw.active_list_lock);
1255         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1256         spin_unlock(&pd->cdrw.active_list_lock);
1257
1258         return 1;
1259 }
1260
1261 /*
1262  * Assemble a bio to write one packet and queue the bio for processing
1263  * by the underlying block device.
1264  */
1265 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1266 {
1267         int f;
1268
1269         bio_reset(pkt->w_bio);
1270         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1271         bio_set_dev(pkt->w_bio, pd->bdev);
1272         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1273         pkt->w_bio->bi_private = pkt;
1274
1275         /* XXX: locking? */
1276         for (f = 0; f < pkt->frames; f++) {
1277                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1278                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1279
1280                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1281                         BUG();
1282         }
1283         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1284
1285         /*
1286          * Fill-in bvec with data from orig_bios.
1287          */
1288         spin_lock(&pkt->lock);
1289         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1290
1291         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1292         spin_unlock(&pkt->lock);
1293
1294         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1295                 pkt->write_size, (unsigned long long)pkt->sector);
1296
1297         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1298                 pkt->cache_valid = 1;
1299         else
1300                 pkt->cache_valid = 0;
1301
1302         /* Start the write request */
1303         atomic_set(&pkt->io_wait, 1);
1304         bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
1305         pkt_queue_bio(pd, pkt->w_bio);
1306 }
1307
1308 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1309 {
1310         struct bio *bio;
1311
1312         if (status)
1313                 pkt->cache_valid = 0;
1314
1315         /* Finish all bios corresponding to this packet */
1316         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1317                 bio->bi_status = status;
1318                 bio_endio(bio);
1319         }
1320 }
1321
1322 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1323 {
1324         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1325
1326         for (;;) {
1327                 switch (pkt->state) {
1328                 case PACKET_WAITING_STATE:
1329                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1330                                 return;
1331
1332                         pkt->sleep_time = 0;
1333                         pkt_gather_data(pd, pkt);
1334                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1335                         break;
1336
1337                 case PACKET_READ_WAIT_STATE:
1338                         if (atomic_read(&pkt->io_wait) > 0)
1339                                 return;
1340
1341                         if (atomic_read(&pkt->io_errors) > 0) {
1342                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1343                         } else {
1344                                 pkt_start_write(pd, pkt);
1345                         }
1346                         break;
1347
1348                 case PACKET_WRITE_WAIT_STATE:
1349                         if (atomic_read(&pkt->io_wait) > 0)
1350                                 return;
1351
1352                         if (!pkt->w_bio->bi_status) {
1353                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1354                         } else {
1355                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1356                         }
1357                         break;
1358
1359                 case PACKET_RECOVERY_STATE:
1360                         if (pkt_start_recovery(pkt)) {
1361                                 pkt_start_write(pd, pkt);
1362                         } else {
1363                                 pkt_dbg(2, pd, "No recovery possible\n");
1364                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1365                         }
1366                         break;
1367
1368                 case PACKET_FINISHED_STATE:
1369                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1370                         return;
1371
1372                 default:
1373                         BUG();
1374                         break;
1375                 }
1376         }
1377 }
1378
1379 static void pkt_handle_packets(struct pktcdvd_device *pd)
1380 {
1381         struct packet_data *pkt, *next;
1382
1383         /*
1384          * Run state machine for active packets
1385          */
1386         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1387                 if (atomic_read(&pkt->run_sm) > 0) {
1388                         atomic_set(&pkt->run_sm, 0);
1389                         pkt_run_state_machine(pd, pkt);
1390                 }
1391         }
1392
1393         /*
1394          * Move no longer active packets to the free list
1395          */
1396         spin_lock(&pd->cdrw.active_list_lock);
1397         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1398                 if (pkt->state == PACKET_FINISHED_STATE) {
1399                         list_del(&pkt->list);
1400                         pkt_put_packet_data(pd, pkt);
1401                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1402                         atomic_set(&pd->scan_queue, 1);
1403                 }
1404         }
1405         spin_unlock(&pd->cdrw.active_list_lock);
1406 }
1407
1408 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1409 {
1410         struct packet_data *pkt;
1411         int i;
1412
1413         for (i = 0; i < PACKET_NUM_STATES; i++)
1414                 states[i] = 0;
1415
1416         spin_lock(&pd->cdrw.active_list_lock);
1417         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1418                 states[pkt->state]++;
1419         }
1420         spin_unlock(&pd->cdrw.active_list_lock);
1421 }
1422
1423 /*
1424  * kcdrwd is woken up when writes have been queued for one of our
1425  * registered devices
1426  */
1427 static int kcdrwd(void *foobar)
1428 {
1429         struct pktcdvd_device *pd = foobar;
1430         struct packet_data *pkt;
1431         long min_sleep_time, residue;
1432
1433         set_user_nice(current, MIN_NICE);
1434         set_freezable();
1435
1436         for (;;) {
1437                 DECLARE_WAITQUEUE(wait, current);
1438
1439                 /*
1440                  * Wait until there is something to do
1441                  */
1442                 add_wait_queue(&pd->wqueue, &wait);
1443                 for (;;) {
1444                         set_current_state(TASK_INTERRUPTIBLE);
1445
1446                         /* Check if we need to run pkt_handle_queue */
1447                         if (atomic_read(&pd->scan_queue) > 0)
1448                                 goto work_to_do;
1449
1450                         /* Check if we need to run the state machine for some packet */
1451                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1452                                 if (atomic_read(&pkt->run_sm) > 0)
1453                                         goto work_to_do;
1454                         }
1455
1456                         /* Check if we need to process the iosched queues */
1457                         if (atomic_read(&pd->iosched.attention) != 0)
1458                                 goto work_to_do;
1459
1460                         /* Otherwise, go to sleep */
1461                         if (PACKET_DEBUG > 1) {
1462                                 int states[PACKET_NUM_STATES];
1463                                 pkt_count_states(pd, states);
1464                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1465                                         states[0], states[1], states[2],
1466                                         states[3], states[4], states[5]);
1467                         }
1468
1469                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1470                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1471                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1472                                         min_sleep_time = pkt->sleep_time;
1473                         }
1474
1475                         pkt_dbg(2, pd, "sleeping\n");
1476                         residue = schedule_timeout(min_sleep_time);
1477                         pkt_dbg(2, pd, "wake up\n");
1478
1479                         /* make swsusp happy with our thread */
1480                         try_to_freeze();
1481
1482                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1483                                 if (!pkt->sleep_time)
1484                                         continue;
1485                                 pkt->sleep_time -= min_sleep_time - residue;
1486                                 if (pkt->sleep_time <= 0) {
1487                                         pkt->sleep_time = 0;
1488                                         atomic_inc(&pkt->run_sm);
1489                                 }
1490                         }
1491
1492                         if (kthread_should_stop())
1493                                 break;
1494                 }
1495 work_to_do:
1496                 set_current_state(TASK_RUNNING);
1497                 remove_wait_queue(&pd->wqueue, &wait);
1498
1499                 if (kthread_should_stop())
1500                         break;
1501
1502                 /*
1503                  * if pkt_handle_queue returns true, we can queue
1504                  * another request.
1505                  */
1506                 while (pkt_handle_queue(pd))
1507                         ;
1508
1509                 /*
1510                  * Handle packet state machine
1511                  */
1512                 pkt_handle_packets(pd);
1513
1514                 /*
1515                  * Handle iosched queues
1516                  */
1517                 pkt_iosched_process_queue(pd);
1518         }
1519
1520         return 0;
1521 }
1522
1523 static void pkt_print_settings(struct pktcdvd_device *pd)
1524 {
1525         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1526                  pd->settings.fp ? "Fixed" : "Variable",
1527                  pd->settings.size >> 2,
1528                  pd->settings.block_mode == 8 ? '1' : '2');
1529 }
1530
1531 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1532 {
1533         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1534
1535         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1536         cgc->cmd[2] = page_code | (page_control << 6);
1537         cgc->cmd[7] = cgc->buflen >> 8;
1538         cgc->cmd[8] = cgc->buflen & 0xff;
1539         cgc->data_direction = CGC_DATA_READ;
1540         return pkt_generic_packet(pd, cgc);
1541 }
1542
1543 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1544 {
1545         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1546         memset(cgc->buffer, 0, 2);
1547         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1548         cgc->cmd[1] = 0x10;             /* PF */
1549         cgc->cmd[7] = cgc->buflen >> 8;
1550         cgc->cmd[8] = cgc->buflen & 0xff;
1551         cgc->data_direction = CGC_DATA_WRITE;
1552         return pkt_generic_packet(pd, cgc);
1553 }
1554
1555 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1556 {
1557         struct packet_command cgc;
1558         int ret;
1559
1560         /* set up command and get the disc info */
1561         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1562         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1563         cgc.cmd[8] = cgc.buflen = 2;
1564         cgc.quiet = 1;
1565
1566         ret = pkt_generic_packet(pd, &cgc);
1567         if (ret)
1568                 return ret;
1569
1570         /* not all drives have the same disc_info length, so requeue
1571          * packet with the length the drive tells us it can supply
1572          */
1573         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1574                      sizeof(di->disc_information_length);
1575
1576         if (cgc.buflen > sizeof(disc_information))
1577                 cgc.buflen = sizeof(disc_information);
1578
1579         cgc.cmd[8] = cgc.buflen;
1580         return pkt_generic_packet(pd, &cgc);
1581 }
1582
1583 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1584 {
1585         struct packet_command cgc;
1586         int ret;
1587
1588         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1589         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1590         cgc.cmd[1] = type & 3;
1591         cgc.cmd[4] = (track & 0xff00) >> 8;
1592         cgc.cmd[5] = track & 0xff;
1593         cgc.cmd[8] = 8;
1594         cgc.quiet = 1;
1595
1596         ret = pkt_generic_packet(pd, &cgc);
1597         if (ret)
1598                 return ret;
1599
1600         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1601                      sizeof(ti->track_information_length);
1602
1603         if (cgc.buflen > sizeof(track_information))
1604                 cgc.buflen = sizeof(track_information);
1605
1606         cgc.cmd[8] = cgc.buflen;
1607         return pkt_generic_packet(pd, &cgc);
1608 }
1609
1610 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1611                                                 long *last_written)
1612 {
1613         disc_information di;
1614         track_information ti;
1615         __u32 last_track;
1616         int ret;
1617
1618         ret = pkt_get_disc_info(pd, &di);
1619         if (ret)
1620                 return ret;
1621
1622         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1623         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1624         if (ret)
1625                 return ret;
1626
1627         /* if this track is blank, try the previous. */
1628         if (ti.blank) {
1629                 last_track--;
1630                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1631                 if (ret)
1632                         return ret;
1633         }
1634
1635         /* if last recorded field is valid, return it. */
1636         if (ti.lra_v) {
1637                 *last_written = be32_to_cpu(ti.last_rec_address);
1638         } else {
1639                 /* make it up instead */
1640                 *last_written = be32_to_cpu(ti.track_start) +
1641                                 be32_to_cpu(ti.track_size);
1642                 if (ti.free_blocks)
1643                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1644         }
1645         return 0;
1646 }
1647
1648 /*
1649  * write mode select package based on pd->settings
1650  */
1651 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1652 {
1653         struct packet_command cgc;
1654         struct scsi_sense_hdr sshdr;
1655         write_param_page *wp;
1656         char buffer[128];
1657         int ret, size;
1658
1659         /* doesn't apply to DVD+RW or DVD-RAM */
1660         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1661                 return 0;
1662
1663         memset(buffer, 0, sizeof(buffer));
1664         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1665         cgc.sshdr = &sshdr;
1666         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1667         if (ret) {
1668                 pkt_dump_sense(pd, &cgc);
1669                 return ret;
1670         }
1671
1672         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1673         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1674         if (size > sizeof(buffer))
1675                 size = sizeof(buffer);
1676
1677         /*
1678          * now get it all
1679          */
1680         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1681         cgc.sshdr = &sshdr;
1682         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1683         if (ret) {
1684                 pkt_dump_sense(pd, &cgc);
1685                 return ret;
1686         }
1687
1688         /*
1689          * write page is offset header + block descriptor length
1690          */
1691         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1692
1693         wp->fp = pd->settings.fp;
1694         wp->track_mode = pd->settings.track_mode;
1695         wp->write_type = pd->settings.write_type;
1696         wp->data_block_type = pd->settings.block_mode;
1697
1698         wp->multi_session = 0;
1699
1700 #ifdef PACKET_USE_LS
1701         wp->link_size = 7;
1702         wp->ls_v = 1;
1703 #endif
1704
1705         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1706                 wp->session_format = 0;
1707                 wp->subhdr2 = 0x20;
1708         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1709                 wp->session_format = 0x20;
1710                 wp->subhdr2 = 8;
1711 #if 0
1712                 wp->mcn[0] = 0x80;
1713                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1714 #endif
1715         } else {
1716                 /*
1717                  * paranoia
1718                  */
1719                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1720                 return 1;
1721         }
1722         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1723
1724         cgc.buflen = cgc.cmd[8] = size;
1725         ret = pkt_mode_select(pd, &cgc);
1726         if (ret) {
1727                 pkt_dump_sense(pd, &cgc);
1728                 return ret;
1729         }
1730
1731         pkt_print_settings(pd);
1732         return 0;
1733 }
1734
1735 /*
1736  * 1 -- we can write to this track, 0 -- we can't
1737  */
1738 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1739 {
1740         switch (pd->mmc3_profile) {
1741                 case 0x1a: /* DVD+RW */
1742                 case 0x12: /* DVD-RAM */
1743                         /* The track is always writable on DVD+RW/DVD-RAM */
1744                         return 1;
1745                 default:
1746                         break;
1747         }
1748
1749         if (!ti->packet || !ti->fp)
1750                 return 0;
1751
1752         /*
1753          * "good" settings as per Mt Fuji.
1754          */
1755         if (ti->rt == 0 && ti->blank == 0)
1756                 return 1;
1757
1758         if (ti->rt == 0 && ti->blank == 1)
1759                 return 1;
1760
1761         if (ti->rt == 1 && ti->blank == 0)
1762                 return 1;
1763
1764         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1765         return 0;
1766 }
1767
1768 /*
1769  * 1 -- we can write to this disc, 0 -- we can't
1770  */
1771 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1772 {
1773         switch (pd->mmc3_profile) {
1774                 case 0x0a: /* CD-RW */
1775                 case 0xffff: /* MMC3 not supported */
1776                         break;
1777                 case 0x1a: /* DVD+RW */
1778                 case 0x13: /* DVD-RW */
1779                 case 0x12: /* DVD-RAM */
1780                         return 1;
1781                 default:
1782                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1783                                 pd->mmc3_profile);
1784                         return 0;
1785         }
1786
1787         /*
1788          * for disc type 0xff we should probably reserve a new track.
1789          * but i'm not sure, should we leave this to user apps? probably.
1790          */
1791         if (di->disc_type == 0xff) {
1792                 pkt_notice(pd, "unknown disc - no track?\n");
1793                 return 0;
1794         }
1795
1796         if (di->disc_type != 0x20 && di->disc_type != 0) {
1797                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1798                 return 0;
1799         }
1800
1801         if (di->erasable == 0) {
1802                 pkt_notice(pd, "disc not erasable\n");
1803                 return 0;
1804         }
1805
1806         if (di->border_status == PACKET_SESSION_RESERVED) {
1807                 pkt_err(pd, "can't write to last track (reserved)\n");
1808                 return 0;
1809         }
1810
1811         return 1;
1812 }
1813
1814 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1815 {
1816         struct packet_command cgc;
1817         unsigned char buf[12];
1818         disc_information di;
1819         track_information ti;
1820         int ret, track;
1821
1822         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1823         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1824         cgc.cmd[8] = 8;
1825         ret = pkt_generic_packet(pd, &cgc);
1826         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1827
1828         memset(&di, 0, sizeof(disc_information));
1829         memset(&ti, 0, sizeof(track_information));
1830
1831         ret = pkt_get_disc_info(pd, &di);
1832         if (ret) {
1833                 pkt_err(pd, "failed get_disc\n");
1834                 return ret;
1835         }
1836
1837         if (!pkt_writable_disc(pd, &di))
1838                 return -EROFS;
1839
1840         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1841
1842         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1843         ret = pkt_get_track_info(pd, track, 1, &ti);
1844         if (ret) {
1845                 pkt_err(pd, "failed get_track\n");
1846                 return ret;
1847         }
1848
1849         if (!pkt_writable_track(pd, &ti)) {
1850                 pkt_err(pd, "can't write to this track\n");
1851                 return -EROFS;
1852         }
1853
1854         /*
1855          * we keep packet size in 512 byte units, makes it easier to
1856          * deal with request calculations.
1857          */
1858         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1859         if (pd->settings.size == 0) {
1860                 pkt_notice(pd, "detected zero packet size!\n");
1861                 return -ENXIO;
1862         }
1863         if (pd->settings.size > PACKET_MAX_SECTORS) {
1864                 pkt_err(pd, "packet size is too big\n");
1865                 return -EROFS;
1866         }
1867         pd->settings.fp = ti.fp;
1868         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1869
1870         if (ti.nwa_v) {
1871                 pd->nwa = be32_to_cpu(ti.next_writable);
1872                 set_bit(PACKET_NWA_VALID, &pd->flags);
1873         }
1874
1875         /*
1876          * in theory we could use lra on -RW media as well and just zero
1877          * blocks that haven't been written yet, but in practice that
1878          * is just a no-go. we'll use that for -R, naturally.
1879          */
1880         if (ti.lra_v) {
1881                 pd->lra = be32_to_cpu(ti.last_rec_address);
1882                 set_bit(PACKET_LRA_VALID, &pd->flags);
1883         } else {
1884                 pd->lra = 0xffffffff;
1885                 set_bit(PACKET_LRA_VALID, &pd->flags);
1886         }
1887
1888         /*
1889          * fine for now
1890          */
1891         pd->settings.link_loss = 7;
1892         pd->settings.write_type = 0;    /* packet */
1893         pd->settings.track_mode = ti.track_mode;
1894
1895         /*
1896          * mode1 or mode2 disc
1897          */
1898         switch (ti.data_mode) {
1899                 case PACKET_MODE1:
1900                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1901                         break;
1902                 case PACKET_MODE2:
1903                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1904                         break;
1905                 default:
1906                         pkt_err(pd, "unknown data mode\n");
1907                         return -EROFS;
1908         }
1909         return 0;
1910 }
1911
1912 /*
1913  * enable/disable write caching on drive
1914  */
1915 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1916                                                 int set)
1917 {
1918         struct packet_command cgc;
1919         struct scsi_sense_hdr sshdr;
1920         unsigned char buf[64];
1921         int ret;
1922
1923         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1924         cgc.sshdr = &sshdr;
1925         cgc.buflen = pd->mode_offset + 12;
1926
1927         /*
1928          * caching mode page might not be there, so quiet this command
1929          */
1930         cgc.quiet = 1;
1931
1932         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1933         if (ret)
1934                 return ret;
1935
1936         buf[pd->mode_offset + 10] |= (!!set << 2);
1937
1938         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1939         ret = pkt_mode_select(pd, &cgc);
1940         if (ret) {
1941                 pkt_err(pd, "write caching control failed\n");
1942                 pkt_dump_sense(pd, &cgc);
1943         } else if (!ret && set)
1944                 pkt_notice(pd, "enabled write caching\n");
1945         return ret;
1946 }
1947
1948 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1949 {
1950         struct packet_command cgc;
1951
1952         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1953         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1954         cgc.cmd[4] = lockflag ? 1 : 0;
1955         return pkt_generic_packet(pd, &cgc);
1956 }
1957
1958 /*
1959  * Returns drive maximum write speed
1960  */
1961 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1962                                                 unsigned *write_speed)
1963 {
1964         struct packet_command cgc;
1965         struct scsi_sense_hdr sshdr;
1966         unsigned char buf[256+18];
1967         unsigned char *cap_buf;
1968         int ret, offset;
1969
1970         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1971         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1972         cgc.sshdr = &sshdr;
1973
1974         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1975         if (ret) {
1976                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1977                              sizeof(struct mode_page_header);
1978                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1979                 if (ret) {
1980                         pkt_dump_sense(pd, &cgc);
1981                         return ret;
1982                 }
1983         }
1984
1985         offset = 20;                        /* Obsoleted field, used by older drives */
1986         if (cap_buf[1] >= 28)
1987                 offset = 28;                /* Current write speed selected */
1988         if (cap_buf[1] >= 30) {
1989                 /* If the drive reports at least one "Logical Unit Write
1990                  * Speed Performance Descriptor Block", use the information
1991                  * in the first block. (contains the highest speed)
1992                  */
1993                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1994                 if (num_spdb > 0)
1995                         offset = 34;
1996         }
1997
1998         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1999         return 0;
2000 }
2001
2002 /* These tables from cdrecord - I don't have orange book */
2003 /* standard speed CD-RW (1-4x) */
2004 static char clv_to_speed[16] = {
2005         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2006            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2007 };
2008 /* high speed CD-RW (-10x) */
2009 static char hs_clv_to_speed[16] = {
2010         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2011            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2012 };
2013 /* ultra high speed CD-RW */
2014 static char us_clv_to_speed[16] = {
2015         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2016            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2017 };
2018
2019 /*
2020  * reads the maximum media speed from ATIP
2021  */
2022 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2023                                                 unsigned *speed)
2024 {
2025         struct packet_command cgc;
2026         struct scsi_sense_hdr sshdr;
2027         unsigned char buf[64];
2028         unsigned int size, st, sp;
2029         int ret;
2030
2031         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2032         cgc.sshdr = &sshdr;
2033         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2034         cgc.cmd[1] = 2;
2035         cgc.cmd[2] = 4; /* READ ATIP */
2036         cgc.cmd[8] = 2;
2037         ret = pkt_generic_packet(pd, &cgc);
2038         if (ret) {
2039                 pkt_dump_sense(pd, &cgc);
2040                 return ret;
2041         }
2042         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2043         if (size > sizeof(buf))
2044                 size = sizeof(buf);
2045
2046         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2047         cgc.sshdr = &sshdr;
2048         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2049         cgc.cmd[1] = 2;
2050         cgc.cmd[2] = 4;
2051         cgc.cmd[8] = size;
2052         ret = pkt_generic_packet(pd, &cgc);
2053         if (ret) {
2054                 pkt_dump_sense(pd, &cgc);
2055                 return ret;
2056         }
2057
2058         if (!(buf[6] & 0x40)) {
2059                 pkt_notice(pd, "disc type is not CD-RW\n");
2060                 return 1;
2061         }
2062         if (!(buf[6] & 0x4)) {
2063                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2064                 return 1;
2065         }
2066
2067         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2068
2069         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2070
2071         /* Info from cdrecord */
2072         switch (st) {
2073                 case 0: /* standard speed */
2074                         *speed = clv_to_speed[sp];
2075                         break;
2076                 case 1: /* high speed */
2077                         *speed = hs_clv_to_speed[sp];
2078                         break;
2079                 case 2: /* ultra high speed */
2080                         *speed = us_clv_to_speed[sp];
2081                         break;
2082                 default:
2083                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2084                         return 1;
2085         }
2086         if (*speed) {
2087                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2088                 return 0;
2089         } else {
2090                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2091                 return 1;
2092         }
2093 }
2094
2095 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2096 {
2097         struct packet_command cgc;
2098         struct scsi_sense_hdr sshdr;
2099         int ret;
2100
2101         pkt_dbg(2, pd, "Performing OPC\n");
2102
2103         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2104         cgc.sshdr = &sshdr;
2105         cgc.timeout = 60*HZ;
2106         cgc.cmd[0] = GPCMD_SEND_OPC;
2107         cgc.cmd[1] = 1;
2108         ret = pkt_generic_packet(pd, &cgc);
2109         if (ret)
2110                 pkt_dump_sense(pd, &cgc);
2111         return ret;
2112 }
2113
2114 static int pkt_open_write(struct pktcdvd_device *pd)
2115 {
2116         int ret;
2117         unsigned int write_speed, media_write_speed, read_speed;
2118
2119         ret = pkt_probe_settings(pd);
2120         if (ret) {
2121                 pkt_dbg(2, pd, "failed probe\n");
2122                 return ret;
2123         }
2124
2125         ret = pkt_set_write_settings(pd);
2126         if (ret) {
2127                 pkt_dbg(1, pd, "failed saving write settings\n");
2128                 return -EIO;
2129         }
2130
2131         pkt_write_caching(pd, USE_WCACHING);
2132
2133         ret = pkt_get_max_speed(pd, &write_speed);
2134         if (ret)
2135                 write_speed = 16 * 177;
2136         switch (pd->mmc3_profile) {
2137                 case 0x13: /* DVD-RW */
2138                 case 0x1a: /* DVD+RW */
2139                 case 0x12: /* DVD-RAM */
2140                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2141                         break;
2142                 default:
2143                         ret = pkt_media_speed(pd, &media_write_speed);
2144                         if (ret)
2145                                 media_write_speed = 16;
2146                         write_speed = min(write_speed, media_write_speed * 177);
2147                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2148                         break;
2149         }
2150         read_speed = write_speed;
2151
2152         ret = pkt_set_speed(pd, write_speed, read_speed);
2153         if (ret) {
2154                 pkt_dbg(1, pd, "couldn't set write speed\n");
2155                 return -EIO;
2156         }
2157         pd->write_speed = write_speed;
2158         pd->read_speed = read_speed;
2159
2160         ret = pkt_perform_opc(pd);
2161         if (ret) {
2162                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2163         }
2164
2165         return 0;
2166 }
2167
2168 /*
2169  * called at open time.
2170  */
2171 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2172 {
2173         int ret;
2174         long lba;
2175         struct request_queue *q;
2176
2177         /*
2178          * We need to re-open the cdrom device without O_NONBLOCK to be able
2179          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2180          * so bdget() can't fail.
2181          */
2182         bdget(pd->bdev->bd_dev);
2183         ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd);
2184         if (ret)
2185                 goto out;
2186
2187         ret = pkt_get_last_written(pd, &lba);
2188         if (ret) {
2189                 pkt_err(pd, "pkt_get_last_written failed\n");
2190                 goto out_putdev;
2191         }
2192
2193         set_capacity(pd->disk, lba << 2);
2194         set_capacity(pd->bdev->bd_disk, lba << 2);
2195         bd_set_size(pd->bdev, (loff_t)lba << 11);
2196
2197         q = bdev_get_queue(pd->bdev);
2198         if (write) {
2199                 ret = pkt_open_write(pd);
2200                 if (ret)
2201                         goto out_putdev;
2202                 /*
2203                  * Some CDRW drives can not handle writes larger than one packet,
2204                  * even if the size is a multiple of the packet size.
2205                  */
2206                 blk_queue_max_hw_sectors(q, pd->settings.size);
2207                 set_bit(PACKET_WRITABLE, &pd->flags);
2208         } else {
2209                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2210                 clear_bit(PACKET_WRITABLE, &pd->flags);
2211         }
2212
2213         ret = pkt_set_segment_merging(pd, q);
2214         if (ret)
2215                 goto out_putdev;
2216
2217         if (write) {
2218                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2219                         pkt_err(pd, "not enough memory for buffers\n");
2220                         ret = -ENOMEM;
2221                         goto out_putdev;
2222                 }
2223                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2224         }
2225
2226         return 0;
2227
2228 out_putdev:
2229         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2230 out:
2231         return ret;
2232 }
2233
2234 /*
2235  * called when the device is closed. makes sure that the device flushes
2236  * the internal cache before we close.
2237  */
2238 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2239 {
2240         if (flush && pkt_flush_cache(pd))
2241                 pkt_dbg(1, pd, "not flushing cache\n");
2242
2243         pkt_lock_door(pd, 0);
2244
2245         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2246         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2247
2248         pkt_shrink_pktlist(pd);
2249 }
2250
2251 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2252 {
2253         if (dev_minor >= MAX_WRITERS)
2254                 return NULL;
2255
2256         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2257         return pkt_devs[dev_minor];
2258 }
2259
2260 static int pkt_open(struct block_device *bdev, fmode_t mode)
2261 {
2262         struct pktcdvd_device *pd = NULL;
2263         int ret;
2264
2265         mutex_lock(&pktcdvd_mutex);
2266         mutex_lock(&ctl_mutex);
2267         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2268         if (!pd) {
2269                 ret = -ENODEV;
2270                 goto out;
2271         }
2272         BUG_ON(pd->refcnt < 0);
2273
2274         pd->refcnt++;
2275         if (pd->refcnt > 1) {
2276                 if ((mode & FMODE_WRITE) &&
2277                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2278                         ret = -EBUSY;
2279                         goto out_dec;
2280                 }
2281         } else {
2282                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2283                 if (ret)
2284                         goto out_dec;
2285                 /*
2286                  * needed here as well, since ext2 (among others) may change
2287                  * the blocksize at mount time
2288                  */
2289                 set_blocksize(bdev, CD_FRAMESIZE);
2290         }
2291
2292         mutex_unlock(&ctl_mutex);
2293         mutex_unlock(&pktcdvd_mutex);
2294         return 0;
2295
2296 out_dec:
2297         pd->refcnt--;
2298 out:
2299         mutex_unlock(&ctl_mutex);
2300         mutex_unlock(&pktcdvd_mutex);
2301         return ret;
2302 }
2303
2304 static void pkt_close(struct gendisk *disk, fmode_t mode)
2305 {
2306         struct pktcdvd_device *pd = disk->private_data;
2307
2308         mutex_lock(&pktcdvd_mutex);
2309         mutex_lock(&ctl_mutex);
2310         pd->refcnt--;
2311         BUG_ON(pd->refcnt < 0);
2312         if (pd->refcnt == 0) {
2313                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2314                 pkt_release_dev(pd, flush);
2315         }
2316         mutex_unlock(&ctl_mutex);
2317         mutex_unlock(&pktcdvd_mutex);
2318 }
2319
2320
2321 static void pkt_end_io_read_cloned(struct bio *bio)
2322 {
2323         struct packet_stacked_data *psd = bio->bi_private;
2324         struct pktcdvd_device *pd = psd->pd;
2325
2326         psd->bio->bi_status = bio->bi_status;
2327         bio_put(bio);
2328         bio_endio(psd->bio);
2329         mempool_free(psd, &psd_pool);
2330         pkt_bio_finished(pd);
2331 }
2332
2333 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2334 {
2335         struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, &pkt_bio_set);
2336         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2337
2338         psd->pd = pd;
2339         psd->bio = bio;
2340         bio_set_dev(cloned_bio, pd->bdev);
2341         cloned_bio->bi_private = psd;
2342         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2343         pd->stats.secs_r += bio_sectors(bio);
2344         pkt_queue_bio(pd, cloned_bio);
2345 }
2346
2347 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2348 {
2349         struct pktcdvd_device *pd = q->queuedata;
2350         sector_t zone;
2351         struct packet_data *pkt;
2352         int was_empty, blocked_bio;
2353         struct pkt_rb_node *node;
2354
2355         zone = get_zone(bio->bi_iter.bi_sector, pd);
2356
2357         /*
2358          * If we find a matching packet in state WAITING or READ_WAIT, we can
2359          * just append this bio to that packet.
2360          */
2361         spin_lock(&pd->cdrw.active_list_lock);
2362         blocked_bio = 0;
2363         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2364                 if (pkt->sector == zone) {
2365                         spin_lock(&pkt->lock);
2366                         if ((pkt->state == PACKET_WAITING_STATE) ||
2367                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2368                                 bio_list_add(&pkt->orig_bios, bio);
2369                                 pkt->write_size +=
2370                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2371                                 if ((pkt->write_size >= pkt->frames) &&
2372                                     (pkt->state == PACKET_WAITING_STATE)) {
2373                                         atomic_inc(&pkt->run_sm);
2374                                         wake_up(&pd->wqueue);
2375                                 }
2376                                 spin_unlock(&pkt->lock);
2377                                 spin_unlock(&pd->cdrw.active_list_lock);
2378                                 return;
2379                         } else {
2380                                 blocked_bio = 1;
2381                         }
2382                         spin_unlock(&pkt->lock);
2383                 }
2384         }
2385         spin_unlock(&pd->cdrw.active_list_lock);
2386
2387         /*
2388          * Test if there is enough room left in the bio work queue
2389          * (queue size >= congestion on mark).
2390          * If not, wait till the work queue size is below the congestion off mark.
2391          */
2392         spin_lock(&pd->lock);
2393         if (pd->write_congestion_on > 0
2394             && pd->bio_queue_size >= pd->write_congestion_on) {
2395                 set_bdi_congested(q->backing_dev_info, BLK_RW_ASYNC);
2396                 do {
2397                         spin_unlock(&pd->lock);
2398                         congestion_wait(BLK_RW_ASYNC, HZ);
2399                         spin_lock(&pd->lock);
2400                 } while(pd->bio_queue_size > pd->write_congestion_off);
2401         }
2402         spin_unlock(&pd->lock);
2403
2404         /*
2405          * No matching packet found. Store the bio in the work queue.
2406          */
2407         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2408         node->bio = bio;
2409         spin_lock(&pd->lock);
2410         BUG_ON(pd->bio_queue_size < 0);
2411         was_empty = (pd->bio_queue_size == 0);
2412         pkt_rbtree_insert(pd, node);
2413         spin_unlock(&pd->lock);
2414
2415         /*
2416          * Wake up the worker thread.
2417          */
2418         atomic_set(&pd->scan_queue, 1);
2419         if (was_empty) {
2420                 /* This wake_up is required for correct operation */
2421                 wake_up(&pd->wqueue);
2422         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2423                 /*
2424                  * This wake up is not required for correct operation,
2425                  * but improves performance in some cases.
2426                  */
2427                 wake_up(&pd->wqueue);
2428         }
2429 }
2430
2431 static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
2432 {
2433         struct pktcdvd_device *pd;
2434         char b[BDEVNAME_SIZE];
2435         struct bio *split;
2436
2437         blk_queue_split(q, &bio);
2438
2439         pd = q->queuedata;
2440         if (!pd) {
2441                 pr_err("%s incorrect request queue\n", bio_devname(bio, b));
2442                 goto end_io;
2443         }
2444
2445         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2446                 (unsigned long long)bio->bi_iter.bi_sector,
2447                 (unsigned long long)bio_end_sector(bio));
2448
2449         /*
2450          * Clone READ bios so we can have our own bi_end_io callback.
2451          */
2452         if (bio_data_dir(bio) == READ) {
2453                 pkt_make_request_read(pd, bio);
2454                 return BLK_QC_T_NONE;
2455         }
2456
2457         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2458                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2459                            (unsigned long long)bio->bi_iter.bi_sector);
2460                 goto end_io;
2461         }
2462
2463         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2464                 pkt_err(pd, "wrong bio size\n");
2465                 goto end_io;
2466         }
2467
2468         do {
2469                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2470                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2471
2472                 if (last_zone != zone) {
2473                         BUG_ON(last_zone != zone + pd->settings.size);
2474
2475                         split = bio_split(bio, last_zone -
2476                                           bio->bi_iter.bi_sector,
2477                                           GFP_NOIO, &pkt_bio_set);
2478                         bio_chain(split, bio);
2479                 } else {
2480                         split = bio;
2481                 }
2482
2483                 pkt_make_request_write(q, split);
2484         } while (split != bio);
2485
2486         return BLK_QC_T_NONE;
2487 end_io:
2488         bio_io_error(bio);
2489         return BLK_QC_T_NONE;
2490 }
2491
2492 static void pkt_init_queue(struct pktcdvd_device *pd)
2493 {
2494         struct request_queue *q = pd->disk->queue;
2495
2496         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2497         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2498         q->queuedata = pd;
2499 }
2500
2501 static int pkt_seq_show(struct seq_file *m, void *p)
2502 {
2503         struct pktcdvd_device *pd = m->private;
2504         char *msg;
2505         char bdev_buf[BDEVNAME_SIZE];
2506         int states[PACKET_NUM_STATES];
2507
2508         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2509                    bdevname(pd->bdev, bdev_buf));
2510
2511         seq_printf(m, "\nSettings:\n");
2512         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2513
2514         if (pd->settings.write_type == 0)
2515                 msg = "Packet";
2516         else
2517                 msg = "Unknown";
2518         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2519
2520         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2521         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2522
2523         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2524
2525         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2526                 msg = "Mode 1";
2527         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2528                 msg = "Mode 2";
2529         else
2530                 msg = "Unknown";
2531         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2532
2533         seq_printf(m, "\nStatistics:\n");
2534         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2535         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2536         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2537         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2538         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2539
2540         seq_printf(m, "\nMisc:\n");
2541         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2542         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2543         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2544         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2545         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2546         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2547
2548         seq_printf(m, "\nQueue state:\n");
2549         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2550         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2551         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2552
2553         pkt_count_states(pd, states);
2554         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2555                    states[0], states[1], states[2], states[3], states[4], states[5]);
2556
2557         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2558                         pd->write_congestion_off,
2559                         pd->write_congestion_on);
2560         return 0;
2561 }
2562
2563 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2564 {
2565         int i;
2566         int ret = 0;
2567         char b[BDEVNAME_SIZE];
2568         struct block_device *bdev;
2569
2570         if (pd->pkt_dev == dev) {
2571                 pkt_err(pd, "recursive setup not allowed\n");
2572                 return -EBUSY;
2573         }
2574         for (i = 0; i < MAX_WRITERS; i++) {
2575                 struct pktcdvd_device *pd2 = pkt_devs[i];
2576                 if (!pd2)
2577                         continue;
2578                 if (pd2->bdev->bd_dev == dev) {
2579                         pkt_err(pd, "%s already setup\n",
2580                                 bdevname(pd2->bdev, b));
2581                         return -EBUSY;
2582                 }
2583                 if (pd2->pkt_dev == dev) {
2584                         pkt_err(pd, "can't chain pktcdvd devices\n");
2585                         return -EBUSY;
2586                 }
2587         }
2588
2589         bdev = bdget(dev);
2590         if (!bdev)
2591                 return -ENOMEM;
2592         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2593         if (ret)
2594                 return ret;
2595         if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
2596                 blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2597                 return -EINVAL;
2598         }
2599
2600         /* This is safe, since we have a reference from open(). */
2601         __module_get(THIS_MODULE);
2602
2603         pd->bdev = bdev;
2604         set_blocksize(bdev, CD_FRAMESIZE);
2605
2606         pkt_init_queue(pd);
2607
2608         atomic_set(&pd->cdrw.pending_bios, 0);
2609         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2610         if (IS_ERR(pd->cdrw.thread)) {
2611                 pkt_err(pd, "can't start kernel thread\n");
2612                 ret = -ENOMEM;
2613                 goto out_mem;
2614         }
2615
2616         proc_create_single_data(pd->name, 0, pkt_proc, pkt_seq_show, pd);
2617         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2618         return 0;
2619
2620 out_mem:
2621         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2622         /* This is safe: open() is still holding a reference. */
2623         module_put(THIS_MODULE);
2624         return ret;
2625 }
2626
2627 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2628 {
2629         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2630         int ret;
2631
2632         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2633                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2634
2635         mutex_lock(&pktcdvd_mutex);
2636         switch (cmd) {
2637         case CDROMEJECT:
2638                 /*
2639                  * The door gets locked when the device is opened, so we
2640                  * have to unlock it or else the eject command fails.
2641                  */
2642                 if (pd->refcnt == 1)
2643                         pkt_lock_door(pd, 0);
2644                 /* fall through */
2645         /*
2646          * forward selected CDROM ioctls to CD-ROM, for UDF
2647          */
2648         case CDROMMULTISESSION:
2649         case CDROMREADTOCENTRY:
2650         case CDROM_LAST_WRITTEN:
2651         case CDROM_SEND_PACKET:
2652         case SCSI_IOCTL_SEND_COMMAND:
2653                 ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2654                 break;
2655
2656         default:
2657                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2658                 ret = -ENOTTY;
2659         }
2660         mutex_unlock(&pktcdvd_mutex);
2661
2662         return ret;
2663 }
2664
2665 static unsigned int pkt_check_events(struct gendisk *disk,
2666                                      unsigned int clearing)
2667 {
2668         struct pktcdvd_device *pd = disk->private_data;
2669         struct gendisk *attached_disk;
2670
2671         if (!pd)
2672                 return 0;
2673         if (!pd->bdev)
2674                 return 0;
2675         attached_disk = pd->bdev->bd_disk;
2676         if (!attached_disk || !attached_disk->fops->check_events)
2677                 return 0;
2678         return attached_disk->fops->check_events(attached_disk, clearing);
2679 }
2680
2681 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2682 {
2683         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2684 }
2685
2686 static const struct block_device_operations pktcdvd_ops = {
2687         .owner =                THIS_MODULE,
2688         .open =                 pkt_open,
2689         .release =              pkt_close,
2690         .ioctl =                pkt_ioctl,
2691         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2692         .check_events =         pkt_check_events,
2693         .devnode =              pkt_devnode,
2694 };
2695
2696 /*
2697  * Set up mapping from pktcdvd device to CD-ROM device.
2698  */
2699 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2700 {
2701         int idx;
2702         int ret = -ENOMEM;
2703         struct pktcdvd_device *pd;
2704         struct gendisk *disk;
2705
2706         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2707
2708         for (idx = 0; idx < MAX_WRITERS; idx++)
2709                 if (!pkt_devs[idx])
2710                         break;
2711         if (idx == MAX_WRITERS) {
2712                 pr_err("max %d writers supported\n", MAX_WRITERS);
2713                 ret = -EBUSY;
2714                 goto out_mutex;
2715         }
2716
2717         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2718         if (!pd)
2719                 goto out_mutex;
2720
2721         ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2722                                         sizeof(struct pkt_rb_node));
2723         if (ret)
2724                 goto out_mem;
2725
2726         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2727         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2728         spin_lock_init(&pd->cdrw.active_list_lock);
2729
2730         spin_lock_init(&pd->lock);
2731         spin_lock_init(&pd->iosched.lock);
2732         bio_list_init(&pd->iosched.read_queue);
2733         bio_list_init(&pd->iosched.write_queue);
2734         sprintf(pd->name, DRIVER_NAME"%d", idx);
2735         init_waitqueue_head(&pd->wqueue);
2736         pd->bio_queue = RB_ROOT;
2737
2738         pd->write_congestion_on  = write_congestion_on;
2739         pd->write_congestion_off = write_congestion_off;
2740
2741         ret = -ENOMEM;
2742         disk = alloc_disk(1);
2743         if (!disk)
2744                 goto out_mem;
2745         pd->disk = disk;
2746         disk->major = pktdev_major;
2747         disk->first_minor = idx;
2748         disk->fops = &pktcdvd_ops;
2749         disk->flags = GENHD_FL_REMOVABLE;
2750         strcpy(disk->disk_name, pd->name);
2751         disk->private_data = pd;
2752         disk->queue = blk_alloc_queue(pkt_make_request, NUMA_NO_NODE);
2753         if (!disk->queue)
2754                 goto out_mem2;
2755
2756         pd->pkt_dev = MKDEV(pktdev_major, idx);
2757         ret = pkt_new_dev(pd, dev);
2758         if (ret)
2759                 goto out_mem2;
2760
2761         /* inherit events of the host device */
2762         disk->events = pd->bdev->bd_disk->events;
2763
2764         add_disk(disk);
2765
2766         pkt_sysfs_dev_new(pd);
2767         pkt_debugfs_dev_new(pd);
2768
2769         pkt_devs[idx] = pd;
2770         if (pkt_dev)
2771                 *pkt_dev = pd->pkt_dev;
2772
2773         mutex_unlock(&ctl_mutex);
2774         return 0;
2775
2776 out_mem2:
2777         put_disk(disk);
2778 out_mem:
2779         mempool_exit(&pd->rb_pool);
2780         kfree(pd);
2781 out_mutex:
2782         mutex_unlock(&ctl_mutex);
2783         pr_err("setup of pktcdvd device failed\n");
2784         return ret;
2785 }
2786
2787 /*
2788  * Tear down mapping from pktcdvd device to CD-ROM device.
2789  */
2790 static int pkt_remove_dev(dev_t pkt_dev)
2791 {
2792         struct pktcdvd_device *pd;
2793         int idx;
2794         int ret = 0;
2795
2796         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2797
2798         for (idx = 0; idx < MAX_WRITERS; idx++) {
2799                 pd = pkt_devs[idx];
2800                 if (pd && (pd->pkt_dev == pkt_dev))
2801                         break;
2802         }
2803         if (idx == MAX_WRITERS) {
2804                 pr_debug("dev not setup\n");
2805                 ret = -ENXIO;
2806                 goto out;
2807         }
2808
2809         if (pd->refcnt > 0) {
2810                 ret = -EBUSY;
2811                 goto out;
2812         }
2813         if (!IS_ERR(pd->cdrw.thread))
2814                 kthread_stop(pd->cdrw.thread);
2815
2816         pkt_devs[idx] = NULL;
2817
2818         pkt_debugfs_dev_remove(pd);
2819         pkt_sysfs_dev_remove(pd);
2820
2821         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2822
2823         remove_proc_entry(pd->name, pkt_proc);
2824         pkt_dbg(1, pd, "writer unmapped\n");
2825
2826         del_gendisk(pd->disk);
2827         blk_cleanup_queue(pd->disk->queue);
2828         put_disk(pd->disk);
2829
2830         mempool_exit(&pd->rb_pool);
2831         kfree(pd);
2832
2833         /* This is safe: open() is still holding a reference. */
2834         module_put(THIS_MODULE);
2835
2836 out:
2837         mutex_unlock(&ctl_mutex);
2838         return ret;
2839 }
2840
2841 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2842 {
2843         struct pktcdvd_device *pd;
2844
2845         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2846
2847         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2848         if (pd) {
2849                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2850                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2851         } else {
2852                 ctrl_cmd->dev = 0;
2853                 ctrl_cmd->pkt_dev = 0;
2854         }
2855         ctrl_cmd->num_devices = MAX_WRITERS;
2856
2857         mutex_unlock(&ctl_mutex);
2858 }
2859
2860 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2861 {
2862         void __user *argp = (void __user *)arg;
2863         struct pkt_ctrl_command ctrl_cmd;
2864         int ret = 0;
2865         dev_t pkt_dev = 0;
2866
2867         if (cmd != PACKET_CTRL_CMD)
2868                 return -ENOTTY;
2869
2870         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2871                 return -EFAULT;
2872
2873         switch (ctrl_cmd.command) {
2874         case PKT_CTRL_CMD_SETUP:
2875                 if (!capable(CAP_SYS_ADMIN))
2876                         return -EPERM;
2877                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2878                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2879                 break;
2880         case PKT_CTRL_CMD_TEARDOWN:
2881                 if (!capable(CAP_SYS_ADMIN))
2882                         return -EPERM;
2883                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2884                 break;
2885         case PKT_CTRL_CMD_STATUS:
2886                 pkt_get_status(&ctrl_cmd);
2887                 break;
2888         default:
2889                 return -ENOTTY;
2890         }
2891
2892         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2893                 return -EFAULT;
2894         return ret;
2895 }
2896
2897 #ifdef CONFIG_COMPAT
2898 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2899 {
2900         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2901 }
2902 #endif
2903
2904 static const struct file_operations pkt_ctl_fops = {
2905         .open           = nonseekable_open,
2906         .unlocked_ioctl = pkt_ctl_ioctl,
2907 #ifdef CONFIG_COMPAT
2908         .compat_ioctl   = pkt_ctl_compat_ioctl,
2909 #endif
2910         .owner          = THIS_MODULE,
2911         .llseek         = no_llseek,
2912 };
2913
2914 static struct miscdevice pkt_misc = {
2915         .minor          = MISC_DYNAMIC_MINOR,
2916         .name           = DRIVER_NAME,
2917         .nodename       = "pktcdvd/control",
2918         .fops           = &pkt_ctl_fops
2919 };
2920
2921 static int __init pkt_init(void)
2922 {
2923         int ret;
2924
2925         mutex_init(&ctl_mutex);
2926
2927         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2928                                     sizeof(struct packet_stacked_data));
2929         if (ret)
2930                 return ret;
2931         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2932         if (ret) {
2933                 mempool_exit(&psd_pool);
2934                 return ret;
2935         }
2936
2937         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2938         if (ret < 0) {
2939                 pr_err("unable to register block device\n");
2940                 goto out2;
2941         }
2942         if (!pktdev_major)
2943                 pktdev_major = ret;
2944
2945         ret = pkt_sysfs_init();
2946         if (ret)
2947                 goto out;
2948
2949         pkt_debugfs_init();
2950
2951         ret = misc_register(&pkt_misc);
2952         if (ret) {
2953                 pr_err("unable to register misc device\n");
2954                 goto out_misc;
2955         }
2956
2957         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2958
2959         return 0;
2960
2961 out_misc:
2962         pkt_debugfs_cleanup();
2963         pkt_sysfs_cleanup();
2964 out:
2965         unregister_blkdev(pktdev_major, DRIVER_NAME);
2966 out2:
2967         mempool_exit(&psd_pool);
2968         bioset_exit(&pkt_bio_set);
2969         return ret;
2970 }
2971
2972 static void __exit pkt_exit(void)
2973 {
2974         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2975         misc_deregister(&pkt_misc);
2976
2977         pkt_debugfs_cleanup();
2978         pkt_sysfs_cleanup();
2979
2980         unregister_blkdev(pktdev_major, DRIVER_NAME);
2981         mempool_exit(&psd_pool);
2982         bioset_exit(&pkt_bio_set);
2983 }
2984
2985 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2986 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2987 MODULE_LICENSE("GPL");
2988
2989 module_init(pkt_init);
2990 module_exit(pkt_exit);