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
  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
 102 static struct class     *class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
 103 static struct dentry    *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
 104
 105 /* forward declaration */
 106 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
 107 static int pkt_remove_dev(dev_t pkt_dev);
 108 static int pkt_seq_show(struct seq_file *m, void *p);
 109
 110 static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
 111 {
 112         return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
 113 }
 114
 115 /*
 116  * create and register a pktcdvd kernel object.
 117  */
 118 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
 119                                         const char* name,
 120                                         struct kobject* parent,
 121                                         struct kobj_type* ktype)
 122 {
 123         struct pktcdvd_kobj *p;
 124         int error;
 125
 126         p = kzalloc(sizeof(*p), GFP_KERNEL);
 127         if (!p)
 128                 return NULL;
 129         p->pd = pd;
 130         error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
 131         if (error) {
 132                 kobject_put(&p->kobj);
 133                 return NULL;
 134         }
 135         kobject_uevent(&p->kobj, KOBJ_ADD);
 136         return p;
 137 }
 138 /*
 139  * remove a pktcdvd kernel object.
 140  */
 141 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 142 {
 143         if (p)
 144                 kobject_put(&p->kobj);
 145 }
 146 /*
 147  * default release function for pktcdvd kernel objects.
 148  */
 149 static void pkt_kobj_release(struct kobject *kobj)
 150 {
 151         kfree(to_pktcdvdkobj(kobj));
 152 }
 153
 154
 155 /**********************************************************
 156  *
 157  * sysfs interface for pktcdvd
 158  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 159  *
 160  **********************************************************/
 161
 162 #define DEF_ATTR(_obj,_name,_mode) \
 163         static struct attribute _obj = { .name = _name, .mode = _mode }
 164
 165 /**********************************************************
 166   /sys/class/pktcdvd/pktcdvd[0-7]/
 167                      stat/reset
 168                      stat/packets_started
 169                      stat/packets_finished
 170                      stat/kb_written
 171                      stat/kb_read
 172                      stat/kb_read_gather
 173                      write_queue/size
 174                      write_queue/congestion_off
 175                      write_queue/congestion_on
 176  **********************************************************/
 177
 178 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 179 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 180 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 181 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 182 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 183 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 184
 185 static struct attribute *kobj_pkt_attrs_stat[] = {
 186         &kobj_pkt_attr_st1,
 187         &kobj_pkt_attr_st2,
 188         &kobj_pkt_attr_st3,
 189         &kobj_pkt_attr_st4,
 190         &kobj_pkt_attr_st5,
 191         &kobj_pkt_attr_st6,
 192         NULL
 193 };
 194
 195 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 196 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 197 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 198
 199 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 200         &kobj_pkt_attr_wq1,
 201         &kobj_pkt_attr_wq2,
 202         &kobj_pkt_attr_wq3,
 203         NULL
 204 };
 205
 206 static ssize_t kobj_pkt_show(struct kobject *kobj,
 207                         struct attribute *attr, char *data)
 208 {
 209         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 210         int n = 0;
 211         int v;
 212         if (strcmp(attr->name, "packets_started") == 0) {
 213                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 214
 215         } else if (strcmp(attr->name, "packets_finished") == 0) {
 216                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 217
 218         } else if (strcmp(attr->name, "kb_written") == 0) {
 219                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 220
 221         } else if (strcmp(attr->name, "kb_read") == 0) {
 222                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 223
 224         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 225                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 226
 227         } else if (strcmp(attr->name, "size") == 0) {
 228                 spin_lock(&pd->lock);
 229                 v = pd->bio_queue_size;
 230                 spin_unlock(&pd->lock);
 231                 n = sprintf(data, "%d\n", v);
 232
 233         } else if (strcmp(attr->name, "congestion_off") == 0) {
 234                 spin_lock(&pd->lock);
 235                 v = pd->write_congestion_off;
 236                 spin_unlock(&pd->lock);
 237                 n = sprintf(data, "%d\n", v);
 238
 239         } else if (strcmp(attr->name, "congestion_on") == 0) {
 240                 spin_lock(&pd->lock);
 241                 v = pd->write_congestion_on;
 242                 spin_unlock(&pd->lock);
 243                 n = sprintf(data, "%d\n", v);
 244         }
 245         return n;
 246 }
 247
 248 static void init_write_congestion_marks(int* lo, int* hi)
 249 {
 250         if (*hi > 0) {
 251                 *hi = max(*hi, 500);
 252                 *hi = min(*hi, 1000000);
 253                 if (*lo <= 0)
 254                         *lo = *hi - 100;
 255                 else {
 256                         *lo = min(*lo, *hi - 100);
 257                         *lo = max(*lo, 100);
 258                 }
 259         } else {
 260                 *hi = -1;
 261                 *lo = -1;
 262         }
 263 }
 264
 265 static ssize_t kobj_pkt_store(struct kobject *kobj,
 266                         struct attribute *attr,
 267                         const char *data, size_t len)
 268 {
 269         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 270         int val;
 271
 272         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 273                 pd->stats.pkt_started = 0;
 274                 pd->stats.pkt_ended = 0;
 275                 pd->stats.secs_w = 0;
 276                 pd->stats.secs_rg = 0;
 277                 pd->stats.secs_r = 0;
 278
 279         } else if (strcmp(attr->name, "congestion_off") == 0
 280                    && sscanf(data, "%d", &val) == 1) {
 281                 spin_lock(&pd->lock);
 282                 pd->write_congestion_off = val;
 283                 init_write_congestion_marks(&pd->write_congestion_off,
 284                                         &pd->write_congestion_on);
 285                 spin_unlock(&pd->lock);
 286
 287         } else if (strcmp(attr->name, "congestion_on") == 0
 288                    && sscanf(data, "%d", &val) == 1) {
 289                 spin_lock(&pd->lock);
 290                 pd->write_congestion_on = val;
 291                 init_write_congestion_marks(&pd->write_congestion_off,
 292                                         &pd->write_congestion_on);
 293                 spin_unlock(&pd->lock);
 294         }
 295         return len;
 296 }
 297
 298 static const struct sysfs_ops kobj_pkt_ops = {
 299         .show = kobj_pkt_show,
 300         .store = kobj_pkt_store
 301 };
 302 static struct kobj_type kobj_pkt_type_stat = {
 303         .release = pkt_kobj_release,
 304         .sysfs_ops = &kobj_pkt_ops,
 305         .default_attrs = kobj_pkt_attrs_stat
 306 };
 307 static struct kobj_type kobj_pkt_type_wqueue = {
 308         .release = pkt_kobj_release,
 309         .sysfs_ops = &kobj_pkt_ops,
 310         .default_attrs = kobj_pkt_attrs_wqueue
 311 };
 312
 313 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 314 {
 315         if (class_pktcdvd) {
 316                 pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
 317                                         "%s", pd->name);
 318                 if (IS_ERR(pd->dev))
 319                         pd->dev = NULL;
 320         }
 321         if (pd->dev) {
 322                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 323                                         &pd->dev->kobj,
 324                                         &kobj_pkt_type_stat);
 325                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 326                                         &pd->dev->kobj,
 327                                         &kobj_pkt_type_wqueue);
 328         }
 329 }
 330
 331 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 332 {
 333         pkt_kobj_remove(pd->kobj_stat);
 334         pkt_kobj_remove(pd->kobj_wqueue);
 335         if (class_pktcdvd)
 336                 device_unregister(pd->dev);
 337 }
 338
 339
 340 /********************************************************************
 341   /sys/class/pktcdvd/
 342                      add            map block device
 343                      remove         unmap packet dev
 344                      device_map     show mappings
 345  *******************************************************************/
 346
 347 static void class_pktcdvd_release(struct class *cls)
 348 {
 349         kfree(cls);
 350 }
 351 static ssize_t class_pktcdvd_show_map(struct class *c,
 352                                         struct class_attribute *attr,
 353                                         char *data)
 354 {
 355         int n = 0;
 356         int idx;
 357         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 358         for (idx = 0; idx < MAX_WRITERS; idx++) {
 359                 struct pktcdvd_device *pd = pkt_devs[idx];
 360                 if (!pd)
 361                         continue;
 362                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 363                         pd->name,
 364                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 365                         MAJOR(pd->bdev->bd_dev),
 366                         MINOR(pd->bdev->bd_dev));
 367         }
 368         mutex_unlock(&ctl_mutex);
 369         return n;
 370 }
 371
 372 static ssize_t class_pktcdvd_store_add(struct class *c,
 373                                         struct class_attribute *attr,
 374                                         const char *buf,
 375                                         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
 394 static ssize_t class_pktcdvd_store_remove(struct class *c,
 395                                           struct class_attribute *attr,
 396                                           const char *buf,
 397                                         size_t count)
 398 {
 399         unsigned int major, minor;
 400         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 401                 pkt_remove_dev(MKDEV(major, minor));
 402                 return count;
 403         }
 404         return -EINVAL;
 405 }
 406
 407 static struct class_attribute class_pktcdvd_attrs[] = {
 408  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
 409  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
 410  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
 411  __ATTR_NULL
 412 };
 413
 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_attrs = class_pktcdvd_attrs;
 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", S_IRUGO,
 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                              WRITE : READ, __GFP_RECLAIM);
 708         if (IS_ERR(rq))
 709                 return PTR_ERR(rq);
 710         blk_rq_set_block_pc(rq);
 711
 712         if (cgc->buflen) {
 713                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 714                                       __GFP_RECLAIM);
 715                 if (ret)
 716                         goto out;
 717         }
 718
 719         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 720         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 721
 722         rq->timeout = 60*HZ;
 723         if (cgc->quiet)
 724                 rq->rq_flags |= RQF_QUIET;
 725
 726         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 727         if (rq->errors)
 728                 ret = -EIO;
 729 out:
 730         blk_put_request(rq);
 731         return ret;
 732 }
 733
 734 static const char *sense_key_string(__u8 index)
 735 {
 736         static const char * const info[] = {
 737                 "No sense", "Recovered error", "Not ready",
 738                 "Medium error", "Hardware error", "Illegal request",
 739                 "Unit attention", "Data protect", "Blank check",
 740         };
 741
 742         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 743 }
 744
 745 /*
 746  * A generic sense dump / resolve mechanism should be implemented across
 747  * all ATAPI + SCSI devices.
 748  */
 749 static void pkt_dump_sense(struct pktcdvd_device *pd,
 750                            struct packet_command *cgc)
 751 {
 752         struct request_sense *sense = cgc->sense;
 753
 754         if (sense)
 755                 pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
 756                         CDROM_PACKET_SIZE, cgc->cmd,
 757                         sense->sense_key, sense->asc, sense->ascq,
 758                         sense_key_string(sense->sense_key));
 759         else
 760                 pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 761 }
 762
 763 /*
 764  * flush the drive cache to media
 765  */
 766 static int pkt_flush_cache(struct pktcdvd_device *pd)
 767 {
 768         struct packet_command cgc;
 769
 770         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 771         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 772         cgc.quiet = 1;
 773
 774         /*
 775          * the IMMED bit -- we default to not setting it, although that
 776          * would allow a much faster close, this is safer
 777          */
 778 #if 0
 779         cgc.cmd[1] = 1 << 1;
 780 #endif
 781         return pkt_generic_packet(pd, &cgc);
 782 }
 783
 784 /*
 785  * speed is given as the normal factor, e.g. 4 for 4x
 786  */
 787 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 788                                 unsigned write_speed, unsigned read_speed)
 789 {
 790         struct packet_command cgc;
 791         struct request_sense sense;
 792         int ret;
 793
 794         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 795         cgc.sense = &sense;
 796         cgc.cmd[0] = GPCMD_SET_SPEED;
 797         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 798         cgc.cmd[3] = read_speed & 0xff;
 799         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 800         cgc.cmd[5] = write_speed & 0xff;
 801
 802         if ((ret = pkt_generic_packet(pd, &cgc)))
 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_error);
 956
 957         if (bio->bi_error)
 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_error);
 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->bi_bdev = 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         pkt->bio->bi_bdev = 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         pkt->w_bio->bi_bdev = 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_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, int error)
1309 {
1310         struct bio *bio;
1311
1312         if (error)
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_error = error;
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_error) {
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_error);
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         if ((ret = pkt_generic_packet(pd, &cgc)))
1567                 return ret;
1568
1569         /* not all drives have the same disc_info length, so requeue
1570          * packet with the length the drive tells us it can supply
1571          */
1572         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1573                      sizeof(di->disc_information_length);
1574
1575         if (cgc.buflen > sizeof(disc_information))
1576                 cgc.buflen = sizeof(disc_information);
1577
1578         cgc.cmd[8] = cgc.buflen;
1579         return pkt_generic_packet(pd, &cgc);
1580 }
1581
1582 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1583 {
1584         struct packet_command cgc;
1585         int ret;
1586
1587         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1588         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1589         cgc.cmd[1] = type & 3;
1590         cgc.cmd[4] = (track & 0xff00) >> 8;
1591         cgc.cmd[5] = track & 0xff;
1592         cgc.cmd[8] = 8;
1593         cgc.quiet = 1;
1594
1595         if ((ret = pkt_generic_packet(pd, &cgc)))
1596                 return ret;
1597
1598         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1599                      sizeof(ti->track_information_length);
1600
1601         if (cgc.buflen > sizeof(track_information))
1602                 cgc.buflen = sizeof(track_information);
1603
1604         cgc.cmd[8] = cgc.buflen;
1605         return pkt_generic_packet(pd, &cgc);
1606 }
1607
1608 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1609                                                 long *last_written)
1610 {
1611         disc_information di;
1612         track_information ti;
1613         __u32 last_track;
1614         int ret = -1;
1615
1616         if ((ret = pkt_get_disc_info(pd, &di)))
1617                 return ret;
1618
1619         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1620         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1621                 return ret;
1622
1623         /* if this track is blank, try the previous. */
1624         if (ti.blank) {
1625                 last_track--;
1626                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1627                         return ret;
1628         }
1629
1630         /* if last recorded field is valid, return it. */
1631         if (ti.lra_v) {
1632                 *last_written = be32_to_cpu(ti.last_rec_address);
1633         } else {
1634                 /* make it up instead */
1635                 *last_written = be32_to_cpu(ti.track_start) +
1636                                 be32_to_cpu(ti.track_size);
1637                 if (ti.free_blocks)
1638                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1639         }
1640         return 0;
1641 }
1642
1643 /*
1644  * write mode select package based on pd->settings
1645  */
1646 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1647 {
1648         struct packet_command cgc;
1649         struct request_sense sense;
1650         write_param_page *wp;
1651         char buffer[128];
1652         int ret, size;
1653
1654         /* doesn't apply to DVD+RW or DVD-RAM */
1655         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1656                 return 0;
1657
1658         memset(buffer, 0, sizeof(buffer));
1659         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1660         cgc.sense = &sense;
1661         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1662                 pkt_dump_sense(pd, &cgc);
1663                 return ret;
1664         }
1665
1666         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1667         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1668         if (size > sizeof(buffer))
1669                 size = sizeof(buffer);
1670
1671         /*
1672          * now get it all
1673          */
1674         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1675         cgc.sense = &sense;
1676         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1677                 pkt_dump_sense(pd, &cgc);
1678                 return ret;
1679         }
1680
1681         /*
1682          * write page is offset header + block descriptor length
1683          */
1684         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1685
1686         wp->fp = pd->settings.fp;
1687         wp->track_mode = pd->settings.track_mode;
1688         wp->write_type = pd->settings.write_type;
1689         wp->data_block_type = pd->settings.block_mode;
1690
1691         wp->multi_session = 0;
1692
1693 #ifdef PACKET_USE_LS
1694         wp->link_size = 7;
1695         wp->ls_v = 1;
1696 #endif
1697
1698         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1699                 wp->session_format = 0;
1700                 wp->subhdr2 = 0x20;
1701         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1702                 wp->session_format = 0x20;
1703                 wp->subhdr2 = 8;
1704 #if 0
1705                 wp->mcn[0] = 0x80;
1706                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1707 #endif
1708         } else {
1709                 /*
1710                  * paranoia
1711                  */
1712                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1713                 return 1;
1714         }
1715         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1716
1717         cgc.buflen = cgc.cmd[8] = size;
1718         if ((ret = pkt_mode_select(pd, &cgc))) {
1719                 pkt_dump_sense(pd, &cgc);
1720                 return ret;
1721         }
1722
1723         pkt_print_settings(pd);
1724         return 0;
1725 }
1726
1727 /*
1728  * 1 -- we can write to this track, 0 -- we can't
1729  */
1730 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1731 {
1732         switch (pd->mmc3_profile) {
1733                 case 0x1a: /* DVD+RW */
1734                 case 0x12: /* DVD-RAM */
1735                         /* The track is always writable on DVD+RW/DVD-RAM */
1736                         return 1;
1737                 default:
1738                         break;
1739         }
1740
1741         if (!ti->packet || !ti->fp)
1742                 return 0;
1743
1744         /*
1745          * "good" settings as per Mt Fuji.
1746          */
1747         if (ti->rt == 0 && ti->blank == 0)
1748                 return 1;
1749
1750         if (ti->rt == 0 && ti->blank == 1)
1751                 return 1;
1752
1753         if (ti->rt == 1 && ti->blank == 0)
1754                 return 1;
1755
1756         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1757         return 0;
1758 }
1759
1760 /*
1761  * 1 -- we can write to this disc, 0 -- we can't
1762  */
1763 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1764 {
1765         switch (pd->mmc3_profile) {
1766                 case 0x0a: /* CD-RW */
1767                 case 0xffff: /* MMC3 not supported */
1768                         break;
1769                 case 0x1a: /* DVD+RW */
1770                 case 0x13: /* DVD-RW */
1771                 case 0x12: /* DVD-RAM */
1772                         return 1;
1773                 default:
1774                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1775                                 pd->mmc3_profile);
1776                         return 0;
1777         }
1778
1779         /*
1780          * for disc type 0xff we should probably reserve a new track.
1781          * but i'm not sure, should we leave this to user apps? probably.
1782          */
1783         if (di->disc_type == 0xff) {
1784                 pkt_notice(pd, "unknown disc - no track?\n");
1785                 return 0;
1786         }
1787
1788         if (di->disc_type != 0x20 && di->disc_type != 0) {
1789                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1790                 return 0;
1791         }
1792
1793         if (di->erasable == 0) {
1794                 pkt_notice(pd, "disc not erasable\n");
1795                 return 0;
1796         }
1797
1798         if (di->border_status == PACKET_SESSION_RESERVED) {
1799                 pkt_err(pd, "can't write to last track (reserved)\n");
1800                 return 0;
1801         }
1802
1803         return 1;
1804 }
1805
1806 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1807 {
1808         struct packet_command cgc;
1809         unsigned char buf[12];
1810         disc_information di;
1811         track_information ti;
1812         int ret, track;
1813
1814         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1815         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1816         cgc.cmd[8] = 8;
1817         ret = pkt_generic_packet(pd, &cgc);
1818         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1819
1820         memset(&di, 0, sizeof(disc_information));
1821         memset(&ti, 0, sizeof(track_information));
1822
1823         if ((ret = pkt_get_disc_info(pd, &di))) {
1824                 pkt_err(pd, "failed get_disc\n");
1825                 return ret;
1826         }
1827
1828         if (!pkt_writable_disc(pd, &di))
1829                 return -EROFS;
1830
1831         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1832
1833         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1834         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1835                 pkt_err(pd, "failed get_track\n");
1836                 return ret;
1837         }
1838
1839         if (!pkt_writable_track(pd, &ti)) {
1840                 pkt_err(pd, "can't write to this track\n");
1841                 return -EROFS;
1842         }
1843
1844         /*
1845          * we keep packet size in 512 byte units, makes it easier to
1846          * deal with request calculations.
1847          */
1848         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1849         if (pd->settings.size == 0) {
1850                 pkt_notice(pd, "detected zero packet size!\n");
1851                 return -ENXIO;
1852         }
1853         if (pd->settings.size > PACKET_MAX_SECTORS) {
1854                 pkt_err(pd, "packet size is too big\n");
1855                 return -EROFS;
1856         }
1857         pd->settings.fp = ti.fp;
1858         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1859
1860         if (ti.nwa_v) {
1861                 pd->nwa = be32_to_cpu(ti.next_writable);
1862                 set_bit(PACKET_NWA_VALID, &pd->flags);
1863         }
1864
1865         /*
1866          * in theory we could use lra on -RW media as well and just zero
1867          * blocks that haven't been written yet, but in practice that
1868          * is just a no-go. we'll use that for -R, naturally.
1869          */
1870         if (ti.lra_v) {
1871                 pd->lra = be32_to_cpu(ti.last_rec_address);
1872                 set_bit(PACKET_LRA_VALID, &pd->flags);
1873         } else {
1874                 pd->lra = 0xffffffff;
1875                 set_bit(PACKET_LRA_VALID, &pd->flags);
1876         }
1877
1878         /*
1879          * fine for now
1880          */
1881         pd->settings.link_loss = 7;
1882         pd->settings.write_type = 0;    /* packet */
1883         pd->settings.track_mode = ti.track_mode;
1884
1885         /*
1886          * mode1 or mode2 disc
1887          */
1888         switch (ti.data_mode) {
1889                 case PACKET_MODE1:
1890                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1891                         break;
1892                 case PACKET_MODE2:
1893                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1894                         break;
1895                 default:
1896                         pkt_err(pd, "unknown data mode\n");
1897                         return -EROFS;
1898         }
1899         return 0;
1900 }
1901
1902 /*
1903  * enable/disable write caching on drive
1904  */
1905 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1906                                                 int set)
1907 {
1908         struct packet_command cgc;
1909         struct request_sense sense;
1910         unsigned char buf[64];
1911         int ret;
1912
1913         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1914         cgc.sense = &sense;
1915         cgc.buflen = pd->mode_offset + 12;
1916
1917         /*
1918          * caching mode page might not be there, so quiet this command
1919          */
1920         cgc.quiet = 1;
1921
1922         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1923                 return ret;
1924
1925         buf[pd->mode_offset + 10] |= (!!set << 2);
1926
1927         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1928         ret = pkt_mode_select(pd, &cgc);
1929         if (ret) {
1930                 pkt_err(pd, "write caching control failed\n");
1931                 pkt_dump_sense(pd, &cgc);
1932         } else if (!ret && set)
1933                 pkt_notice(pd, "enabled write caching\n");
1934         return ret;
1935 }
1936
1937 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1938 {
1939         struct packet_command cgc;
1940
1941         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1942         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1943         cgc.cmd[4] = lockflag ? 1 : 0;
1944         return pkt_generic_packet(pd, &cgc);
1945 }
1946
1947 /*
1948  * Returns drive maximum write speed
1949  */
1950 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1951                                                 unsigned *write_speed)
1952 {
1953         struct packet_command cgc;
1954         struct request_sense sense;
1955         unsigned char buf[256+18];
1956         unsigned char *cap_buf;
1957         int ret, offset;
1958
1959         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1960         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1961         cgc.sense = &sense;
1962
1963         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1964         if (ret) {
1965                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1966                              sizeof(struct mode_page_header);
1967                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1968                 if (ret) {
1969                         pkt_dump_sense(pd, &cgc);
1970                         return ret;
1971                 }
1972         }
1973
1974         offset = 20;                        /* Obsoleted field, used by older drives */
1975         if (cap_buf[1] >= 28)
1976                 offset = 28;                /* Current write speed selected */
1977         if (cap_buf[1] >= 30) {
1978                 /* If the drive reports at least one "Logical Unit Write
1979                  * Speed Performance Descriptor Block", use the information
1980                  * in the first block. (contains the highest speed)
1981                  */
1982                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1983                 if (num_spdb > 0)
1984                         offset = 34;
1985         }
1986
1987         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1988         return 0;
1989 }
1990
1991 /* These tables from cdrecord - I don't have orange book */
1992 /* standard speed CD-RW (1-4x) */
1993 static char clv_to_speed[16] = {
1994         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1995            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1996 };
1997 /* high speed CD-RW (-10x) */
1998 static char hs_clv_to_speed[16] = {
1999         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2000            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2001 };
2002 /* ultra high speed CD-RW */
2003 static char us_clv_to_speed[16] = {
2004         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2005            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2006 };
2007
2008 /*
2009  * reads the maximum media speed from ATIP
2010  */
2011 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2012                                                 unsigned *speed)
2013 {
2014         struct packet_command cgc;
2015         struct request_sense sense;
2016         unsigned char buf[64];
2017         unsigned int size, st, sp;
2018         int ret;
2019
2020         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2021         cgc.sense = &sense;
2022         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2023         cgc.cmd[1] = 2;
2024         cgc.cmd[2] = 4; /* READ ATIP */
2025         cgc.cmd[8] = 2;
2026         ret = pkt_generic_packet(pd, &cgc);
2027         if (ret) {
2028                 pkt_dump_sense(pd, &cgc);
2029                 return ret;
2030         }
2031         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2032         if (size > sizeof(buf))
2033                 size = sizeof(buf);
2034
2035         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2036         cgc.sense = &sense;
2037         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2038         cgc.cmd[1] = 2;
2039         cgc.cmd[2] = 4;
2040         cgc.cmd[8] = size;
2041         ret = pkt_generic_packet(pd, &cgc);
2042         if (ret) {
2043                 pkt_dump_sense(pd, &cgc);
2044                 return ret;
2045         }
2046
2047         if (!(buf[6] & 0x40)) {
2048                 pkt_notice(pd, "disc type is not CD-RW\n");
2049                 return 1;
2050         }
2051         if (!(buf[6] & 0x4)) {
2052                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2053                 return 1;
2054         }
2055
2056         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2057
2058         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2059
2060         /* Info from cdrecord */
2061         switch (st) {
2062                 case 0: /* standard speed */
2063                         *speed = clv_to_speed[sp];
2064                         break;
2065                 case 1: /* high speed */
2066                         *speed = hs_clv_to_speed[sp];
2067                         break;
2068                 case 2: /* ultra high speed */
2069                         *speed = us_clv_to_speed[sp];
2070                         break;
2071                 default:
2072                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2073                         return 1;
2074         }
2075         if (*speed) {
2076                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2077                 return 0;
2078         } else {
2079                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2080                 return 1;
2081         }
2082 }
2083
2084 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2085 {
2086         struct packet_command cgc;
2087         struct request_sense sense;
2088         int ret;
2089
2090         pkt_dbg(2, pd, "Performing OPC\n");
2091
2092         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2093         cgc.sense = &sense;
2094         cgc.timeout = 60*HZ;
2095         cgc.cmd[0] = GPCMD_SEND_OPC;
2096         cgc.cmd[1] = 1;
2097         if ((ret = pkt_generic_packet(pd, &cgc)))
2098                 pkt_dump_sense(pd, &cgc);
2099         return ret;
2100 }
2101
2102 static int pkt_open_write(struct pktcdvd_device *pd)
2103 {
2104         int ret;
2105         unsigned int write_speed, media_write_speed, read_speed;
2106
2107         if ((ret = pkt_probe_settings(pd))) {
2108                 pkt_dbg(2, pd, "failed probe\n");
2109                 return ret;
2110         }
2111
2112         if ((ret = pkt_set_write_settings(pd))) {
2113                 pkt_dbg(1, pd, "failed saving write settings\n");
2114                 return -EIO;
2115         }
2116
2117         pkt_write_caching(pd, USE_WCACHING);
2118
2119         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2120                 write_speed = 16 * 177;
2121         switch (pd->mmc3_profile) {
2122                 case 0x13: /* DVD-RW */
2123                 case 0x1a: /* DVD+RW */
2124                 case 0x12: /* DVD-RAM */
2125                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2126                         break;
2127                 default:
2128                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2129                                 media_write_speed = 16;
2130                         write_speed = min(write_speed, media_write_speed * 177);
2131                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2132                         break;
2133         }
2134         read_speed = write_speed;
2135
2136         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2137                 pkt_dbg(1, pd, "couldn't set write speed\n");
2138                 return -EIO;
2139         }
2140         pd->write_speed = write_speed;
2141         pd->read_speed = read_speed;
2142
2143         if ((ret = pkt_perform_opc(pd))) {
2144                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2145         }
2146
2147         return 0;
2148 }
2149
2150 /*
2151  * called at open time.
2152  */
2153 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2154 {
2155         int ret;
2156         long lba;
2157         struct request_queue *q;
2158
2159         /*
2160          * We need to re-open the cdrom device without O_NONBLOCK to be able
2161          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2162          * so bdget() can't fail.
2163          */
2164         bdget(pd->bdev->bd_dev);
2165         if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2166                 goto out;
2167
2168         if ((ret = pkt_get_last_written(pd, &lba))) {
2169                 pkt_err(pd, "pkt_get_last_written failed\n");
2170                 goto out_putdev;
2171         }
2172
2173         set_capacity(pd->disk, lba << 2);
2174         set_capacity(pd->bdev->bd_disk, lba << 2);
2175         bd_set_size(pd->bdev, (loff_t)lba << 11);
2176
2177         q = bdev_get_queue(pd->bdev);
2178         if (write) {
2179                 if ((ret = pkt_open_write(pd)))
2180                         goto out_putdev;
2181                 /*
2182                  * Some CDRW drives can not handle writes larger than one packet,
2183                  * even if the size is a multiple of the packet size.
2184                  */
2185                 spin_lock_irq(q->queue_lock);
2186                 blk_queue_max_hw_sectors(q, pd->settings.size);
2187                 spin_unlock_irq(q->queue_lock);
2188                 set_bit(PACKET_WRITABLE, &pd->flags);
2189         } else {
2190                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2191                 clear_bit(PACKET_WRITABLE, &pd->flags);
2192         }
2193
2194         if ((ret = pkt_set_segment_merging(pd, q)))
2195                 goto out_putdev;
2196
2197         if (write) {
2198                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2199                         pkt_err(pd, "not enough memory for buffers\n");
2200                         ret = -ENOMEM;
2201                         goto out_putdev;
2202                 }
2203                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2204         }
2205
2206         return 0;
2207
2208 out_putdev:
2209         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2210 out:
2211         return ret;
2212 }
2213
2214 /*
2215  * called when the device is closed. makes sure that the device flushes
2216  * the internal cache before we close.
2217  */
2218 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2219 {
2220         if (flush && pkt_flush_cache(pd))
2221                 pkt_dbg(1, pd, "not flushing cache\n");
2222
2223         pkt_lock_door(pd, 0);
2224
2225         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2226         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2227
2228         pkt_shrink_pktlist(pd);
2229 }
2230
2231 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2232 {
2233         if (dev_minor >= MAX_WRITERS)
2234                 return NULL;
2235         return pkt_devs[dev_minor];
2236 }
2237
2238 static int pkt_open(struct block_device *bdev, fmode_t mode)
2239 {
2240         struct pktcdvd_device *pd = NULL;
2241         int ret;
2242
2243         mutex_lock(&pktcdvd_mutex);
2244         mutex_lock(&ctl_mutex);
2245         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2246         if (!pd) {
2247                 ret = -ENODEV;
2248                 goto out;
2249         }
2250         BUG_ON(pd->refcnt < 0);
2251
2252         pd->refcnt++;
2253         if (pd->refcnt > 1) {
2254                 if ((mode & FMODE_WRITE) &&
2255                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2256                         ret = -EBUSY;
2257                         goto out_dec;
2258                 }
2259         } else {
2260                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2261                 if (ret)
2262                         goto out_dec;
2263                 /*
2264                  * needed here as well, since ext2 (among others) may change
2265                  * the blocksize at mount time
2266                  */
2267                 set_blocksize(bdev, CD_FRAMESIZE);
2268         }
2269
2270         mutex_unlock(&ctl_mutex);
2271         mutex_unlock(&pktcdvd_mutex);
2272         return 0;
2273
2274 out_dec:
2275         pd->refcnt--;
2276 out:
2277         mutex_unlock(&ctl_mutex);
2278         mutex_unlock(&pktcdvd_mutex);
2279         return ret;
2280 }
2281
2282 static void pkt_close(struct gendisk *disk, fmode_t mode)
2283 {
2284         struct pktcdvd_device *pd = disk->private_data;
2285
2286         mutex_lock(&pktcdvd_mutex);
2287         mutex_lock(&ctl_mutex);
2288         pd->refcnt--;
2289         BUG_ON(pd->refcnt < 0);
2290         if (pd->refcnt == 0) {
2291                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2292                 pkt_release_dev(pd, flush);
2293         }
2294         mutex_unlock(&ctl_mutex);
2295         mutex_unlock(&pktcdvd_mutex);
2296 }
2297
2298
2299 static void pkt_end_io_read_cloned(struct bio *bio)
2300 {
2301         struct packet_stacked_data *psd = bio->bi_private;
2302         struct pktcdvd_device *pd = psd->pd;
2303
2304         psd->bio->bi_error = bio->bi_error;
2305         bio_put(bio);
2306         bio_endio(psd->bio);
2307         mempool_free(psd, psd_pool);
2308         pkt_bio_finished(pd);
2309 }
2310
2311 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2312 {
2313         struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2314         struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2315
2316         psd->pd = pd;
2317         psd->bio = bio;
2318         cloned_bio->bi_bdev = pd->bdev;
2319         cloned_bio->bi_private = psd;
2320         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2321         pd->stats.secs_r += bio_sectors(bio);
2322         pkt_queue_bio(pd, cloned_bio);
2323 }
2324
2325 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2326 {
2327         struct pktcdvd_device *pd = q->queuedata;
2328         sector_t zone;
2329         struct packet_data *pkt;
2330         int was_empty, blocked_bio;
2331         struct pkt_rb_node *node;
2332
2333         zone = get_zone(bio->bi_iter.bi_sector, pd);
2334
2335         /*
2336          * If we find a matching packet in state WAITING or READ_WAIT, we can
2337          * just append this bio to that packet.
2338          */
2339         spin_lock(&pd->cdrw.active_list_lock);
2340         blocked_bio = 0;
2341         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2342                 if (pkt->sector == zone) {
2343                         spin_lock(&pkt->lock);
2344                         if ((pkt->state == PACKET_WAITING_STATE) ||
2345                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2346                                 bio_list_add(&pkt->orig_bios, bio);
2347                                 pkt->write_size +=
2348                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2349                                 if ((pkt->write_size >= pkt->frames) &&
2350                                     (pkt->state == PACKET_WAITING_STATE)) {
2351                                         atomic_inc(&pkt->run_sm);
2352                                         wake_up(&pd->wqueue);
2353                                 }
2354                                 spin_unlock(&pkt->lock);
2355                                 spin_unlock(&pd->cdrw.active_list_lock);
2356                                 return;
2357                         } else {
2358                                 blocked_bio = 1;
2359                         }
2360                         spin_unlock(&pkt->lock);
2361                 }
2362         }
2363         spin_unlock(&pd->cdrw.active_list_lock);
2364
2365         /*
2366          * Test if there is enough room left in the bio work queue
2367          * (queue size >= congestion on mark).
2368          * If not, wait till the work queue size is below the congestion off mark.
2369          */
2370         spin_lock(&pd->lock);
2371         if (pd->write_congestion_on > 0
2372             && pd->bio_queue_size >= pd->write_congestion_on) {
2373                 set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2374                 do {
2375                         spin_unlock(&pd->lock);
2376                         congestion_wait(BLK_RW_ASYNC, HZ);
2377                         spin_lock(&pd->lock);
2378                 } while(pd->bio_queue_size > pd->write_congestion_off);
2379         }
2380         spin_unlock(&pd->lock);
2381
2382         /*
2383          * No matching packet found. Store the bio in the work queue.
2384          */
2385         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2386         node->bio = bio;
2387         spin_lock(&pd->lock);
2388         BUG_ON(pd->bio_queue_size < 0);
2389         was_empty = (pd->bio_queue_size == 0);
2390         pkt_rbtree_insert(pd, node);
2391         spin_unlock(&pd->lock);
2392
2393         /*
2394          * Wake up the worker thread.
2395          */
2396         atomic_set(&pd->scan_queue, 1);
2397         if (was_empty) {
2398                 /* This wake_up is required for correct operation */
2399                 wake_up(&pd->wqueue);
2400         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2401                 /*
2402                  * This wake up is not required for correct operation,
2403                  * but improves performance in some cases.
2404                  */
2405                 wake_up(&pd->wqueue);
2406         }
2407 }
2408
2409 static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
2410 {
2411         struct pktcdvd_device *pd;
2412         char b[BDEVNAME_SIZE];
2413         struct bio *split;
2414
2415         blk_queue_bounce(q, &bio);
2416
2417         blk_queue_split(q, &bio, q->bio_split);
2418
2419         pd = q->queuedata;
2420         if (!pd) {
2421                 pr_err("%s incorrect request queue\n",
2422                        bdevname(bio->bi_bdev, b));
2423                 goto end_io;
2424         }
2425
2426         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2427                 (unsigned long long)bio->bi_iter.bi_sector,
2428                 (unsigned long long)bio_end_sector(bio));
2429
2430         /*
2431          * Clone READ bios so we can have our own bi_end_io callback.
2432          */
2433         if (bio_data_dir(bio) == READ) {
2434                 pkt_make_request_read(pd, bio);
2435                 return BLK_QC_T_NONE;
2436         }
2437
2438         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2439                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2440                            (unsigned long long)bio->bi_iter.bi_sector);
2441                 goto end_io;
2442         }
2443
2444         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2445                 pkt_err(pd, "wrong bio size\n");
2446                 goto end_io;
2447         }
2448
2449         do {
2450                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2451                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2452
2453                 if (last_zone != zone) {
2454                         BUG_ON(last_zone != zone + pd->settings.size);
2455
2456                         split = bio_split(bio, last_zone -
2457                                           bio->bi_iter.bi_sector,
2458                                           GFP_NOIO, fs_bio_set);
2459                         bio_chain(split, bio);
2460                 } else {
2461                         split = bio;
2462                 }
2463
2464                 pkt_make_request_write(q, split);
2465         } while (split != bio);
2466
2467         return BLK_QC_T_NONE;
2468 end_io:
2469         bio_io_error(bio);
2470         return BLK_QC_T_NONE;
2471 }
2472
2473 static void pkt_init_queue(struct pktcdvd_device *pd)
2474 {
2475         struct request_queue *q = pd->disk->queue;
2476
2477         blk_queue_make_request(q, pkt_make_request);
2478         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2479         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2480         q->queuedata = pd;
2481 }
2482
2483 static int pkt_seq_show(struct seq_file *m, void *p)
2484 {
2485         struct pktcdvd_device *pd = m->private;
2486         char *msg;
2487         char bdev_buf[BDEVNAME_SIZE];
2488         int states[PACKET_NUM_STATES];
2489
2490         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2491                    bdevname(pd->bdev, bdev_buf));
2492
2493         seq_printf(m, "\nSettings:\n");
2494         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2495
2496         if (pd->settings.write_type == 0)
2497                 msg = "Packet";
2498         else
2499                 msg = "Unknown";
2500         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2501
2502         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2503         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2504
2505         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2506
2507         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2508                 msg = "Mode 1";
2509         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2510                 msg = "Mode 2";
2511         else
2512                 msg = "Unknown";
2513         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2514
2515         seq_printf(m, "\nStatistics:\n");
2516         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2517         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2518         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2519         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2520         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2521
2522         seq_printf(m, "\nMisc:\n");
2523         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2524         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2525         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2526         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2527         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2528         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2529
2530         seq_printf(m, "\nQueue state:\n");
2531         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2532         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2533         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2534
2535         pkt_count_states(pd, states);
2536         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2537                    states[0], states[1], states[2], states[3], states[4], states[5]);
2538
2539         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2540                         pd->write_congestion_off,
2541                         pd->write_congestion_on);
2542         return 0;
2543 }
2544
2545 static int pkt_seq_open(struct inode *inode, struct file *file)
2546 {
2547         return single_open(file, pkt_seq_show, PDE_DATA(inode));
2548 }
2549
2550 static const struct file_operations pkt_proc_fops = {
2551         .open   = pkt_seq_open,
2552         .read   = seq_read,
2553         .llseek = seq_lseek,
2554         .release = single_release
2555 };
2556
2557 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2558 {
2559         int i;
2560         int ret = 0;
2561         char b[BDEVNAME_SIZE];
2562         struct block_device *bdev;
2563
2564         if (pd->pkt_dev == dev) {
2565                 pkt_err(pd, "recursive setup not allowed\n");
2566                 return -EBUSY;
2567         }
2568         for (i = 0; i < MAX_WRITERS; i++) {
2569                 struct pktcdvd_device *pd2 = pkt_devs[i];
2570                 if (!pd2)
2571                         continue;
2572                 if (pd2->bdev->bd_dev == dev) {
2573                         pkt_err(pd, "%s already setup\n",
2574                                 bdevname(pd2->bdev, b));
2575                         return -EBUSY;
2576                 }
2577                 if (pd2->pkt_dev == dev) {
2578                         pkt_err(pd, "can't chain pktcdvd devices\n");
2579                         return -EBUSY;
2580                 }
2581         }
2582
2583         bdev = bdget(dev);
2584         if (!bdev)
2585                 return -ENOMEM;
2586         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2587         if (ret)
2588                 return ret;
2589
2590         /* This is safe, since we have a reference from open(). */
2591         __module_get(THIS_MODULE);
2592
2593         pd->bdev = bdev;
2594         set_blocksize(bdev, CD_FRAMESIZE);
2595
2596         pkt_init_queue(pd);
2597
2598         atomic_set(&pd->cdrw.pending_bios, 0);
2599         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2600         if (IS_ERR(pd->cdrw.thread)) {
2601                 pkt_err(pd, "can't start kernel thread\n");
2602                 ret = -ENOMEM;
2603                 goto out_mem;
2604         }
2605
2606         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2607         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2608         return 0;
2609
2610 out_mem:
2611         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2612         /* This is safe: open() is still holding a reference. */
2613         module_put(THIS_MODULE);
2614         return ret;
2615 }
2616
2617 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2618 {
2619         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2620         int ret;
2621
2622         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2623                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2624
2625         mutex_lock(&pktcdvd_mutex);
2626         switch (cmd) {
2627         case CDROMEJECT:
2628                 /*
2629                  * The door gets locked when the device is opened, so we
2630                  * have to unlock it or else the eject command fails.
2631                  */
2632                 if (pd->refcnt == 1)
2633                         pkt_lock_door(pd, 0);
2634                 /* fallthru */
2635         /*
2636          * forward selected CDROM ioctls to CD-ROM, for UDF
2637          */
2638         case CDROMMULTISESSION:
2639         case CDROMREADTOCENTRY:
2640         case CDROM_LAST_WRITTEN:
2641         case CDROM_SEND_PACKET:
2642         case SCSI_IOCTL_SEND_COMMAND:
2643                 ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2644                 break;
2645
2646         default:
2647                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2648                 ret = -ENOTTY;
2649         }
2650         mutex_unlock(&pktcdvd_mutex);
2651
2652         return ret;
2653 }
2654
2655 static unsigned int pkt_check_events(struct gendisk *disk,
2656                                      unsigned int clearing)
2657 {
2658         struct pktcdvd_device *pd = disk->private_data;
2659         struct gendisk *attached_disk;
2660
2661         if (!pd)
2662                 return 0;
2663         if (!pd->bdev)
2664                 return 0;
2665         attached_disk = pd->bdev->bd_disk;
2666         if (!attached_disk || !attached_disk->fops->check_events)
2667                 return 0;
2668         return attached_disk->fops->check_events(attached_disk, clearing);
2669 }
2670
2671 static const struct block_device_operations pktcdvd_ops = {
2672         .owner =                THIS_MODULE,
2673         .open =                 pkt_open,
2674         .release =              pkt_close,
2675         .ioctl =                pkt_ioctl,
2676         .check_events =         pkt_check_events,
2677 };
2678
2679 static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2680 {
2681         return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2682 }
2683
2684 /*
2685  * Set up mapping from pktcdvd device to CD-ROM device.
2686  */
2687 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2688 {
2689         int idx;
2690         int ret = -ENOMEM;
2691         struct pktcdvd_device *pd;
2692         struct gendisk *disk;
2693
2694         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2695
2696         for (idx = 0; idx < MAX_WRITERS; idx++)
2697                 if (!pkt_devs[idx])
2698                         break;
2699         if (idx == MAX_WRITERS) {
2700                 pr_err("max %d writers supported\n", MAX_WRITERS);
2701                 ret = -EBUSY;
2702                 goto out_mutex;
2703         }
2704
2705         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2706         if (!pd)
2707                 goto out_mutex;
2708
2709         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2710                                                   sizeof(struct pkt_rb_node));
2711         if (!pd->rb_pool)
2712                 goto out_mem;
2713
2714         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2715         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2716         spin_lock_init(&pd->cdrw.active_list_lock);
2717
2718         spin_lock_init(&pd->lock);
2719         spin_lock_init(&pd->iosched.lock);
2720         bio_list_init(&pd->iosched.read_queue);
2721         bio_list_init(&pd->iosched.write_queue);
2722         sprintf(pd->name, DRIVER_NAME"%d", idx);
2723         init_waitqueue_head(&pd->wqueue);
2724         pd->bio_queue = RB_ROOT;
2725
2726         pd->write_congestion_on  = write_congestion_on;
2727         pd->write_congestion_off = write_congestion_off;
2728
2729         disk = alloc_disk(1);
2730         if (!disk)
2731                 goto out_mem;
2732         pd->disk = disk;
2733         disk->major = pktdev_major;
2734         disk->first_minor = idx;
2735         disk->fops = &pktcdvd_ops;
2736         disk->flags = GENHD_FL_REMOVABLE;
2737         strcpy(disk->disk_name, pd->name);
2738         disk->devnode = pktcdvd_devnode;
2739         disk->private_data = pd;
2740         disk->queue = blk_alloc_queue(GFP_KERNEL);
2741         if (!disk->queue)
2742                 goto out_mem2;
2743
2744         pd->pkt_dev = MKDEV(pktdev_major, idx);
2745         ret = pkt_new_dev(pd, dev);
2746         if (ret)
2747                 goto out_new_dev;
2748
2749         /* inherit events of the host device */
2750         disk->events = pd->bdev->bd_disk->events;
2751         disk->async_events = pd->bdev->bd_disk->async_events;
2752
2753         add_disk(disk);
2754
2755         pkt_sysfs_dev_new(pd);
2756         pkt_debugfs_dev_new(pd);
2757
2758         pkt_devs[idx] = pd;
2759         if (pkt_dev)
2760                 *pkt_dev = pd->pkt_dev;
2761
2762         mutex_unlock(&ctl_mutex);
2763         return 0;
2764
2765 out_new_dev:
2766         blk_cleanup_queue(disk->queue);
2767 out_mem2:
2768         put_disk(disk);
2769 out_mem:
2770         mempool_destroy(pd->rb_pool);
2771         kfree(pd);
2772 out_mutex:
2773         mutex_unlock(&ctl_mutex);
2774         pr_err("setup of pktcdvd device failed\n");
2775         return ret;
2776 }
2777
2778 /*
2779  * Tear down mapping from pktcdvd device to CD-ROM device.
2780  */
2781 static int pkt_remove_dev(dev_t pkt_dev)
2782 {
2783         struct pktcdvd_device *pd;
2784         int idx;
2785         int ret = 0;
2786
2787         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2788
2789         for (idx = 0; idx < MAX_WRITERS; idx++) {
2790                 pd = pkt_devs[idx];
2791                 if (pd && (pd->pkt_dev == pkt_dev))
2792                         break;
2793         }
2794         if (idx == MAX_WRITERS) {
2795                 pr_debug("dev not setup\n");
2796                 ret = -ENXIO;
2797                 goto out;
2798         }
2799
2800         if (pd->refcnt > 0) {
2801                 ret = -EBUSY;
2802                 goto out;
2803         }
2804         if (!IS_ERR(pd->cdrw.thread))
2805                 kthread_stop(pd->cdrw.thread);
2806
2807         pkt_devs[idx] = NULL;
2808
2809         pkt_debugfs_dev_remove(pd);
2810         pkt_sysfs_dev_remove(pd);
2811
2812         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2813
2814         remove_proc_entry(pd->name, pkt_proc);
2815         pkt_dbg(1, pd, "writer unmapped\n");
2816
2817         del_gendisk(pd->disk);
2818         blk_cleanup_queue(pd->disk->queue);
2819         put_disk(pd->disk);
2820
2821         mempool_destroy(pd->rb_pool);
2822         kfree(pd);
2823
2824         /* This is safe: open() is still holding a reference. */
2825         module_put(THIS_MODULE);
2826
2827 out:
2828         mutex_unlock(&ctl_mutex);
2829         return ret;
2830 }
2831
2832 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2833 {
2834         struct pktcdvd_device *pd;
2835
2836         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2837
2838         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2839         if (pd) {
2840                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2841                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2842         } else {
2843                 ctrl_cmd->dev = 0;
2844                 ctrl_cmd->pkt_dev = 0;
2845         }
2846         ctrl_cmd->num_devices = MAX_WRITERS;
2847
2848         mutex_unlock(&ctl_mutex);
2849 }
2850
2851 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2852 {
2853         void __user *argp = (void __user *)arg;
2854         struct pkt_ctrl_command ctrl_cmd;
2855         int ret = 0;
2856         dev_t pkt_dev = 0;
2857
2858         if (cmd != PACKET_CTRL_CMD)
2859                 return -ENOTTY;
2860
2861         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2862                 return -EFAULT;
2863
2864         switch (ctrl_cmd.command) {
2865         case PKT_CTRL_CMD_SETUP:
2866                 if (!capable(CAP_SYS_ADMIN))
2867                         return -EPERM;
2868                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2869                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2870                 break;
2871         case PKT_CTRL_CMD_TEARDOWN:
2872                 if (!capable(CAP_SYS_ADMIN))
2873                         return -EPERM;
2874                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2875                 break;
2876         case PKT_CTRL_CMD_STATUS:
2877                 pkt_get_status(&ctrl_cmd);
2878                 break;
2879         default:
2880                 return -ENOTTY;
2881         }
2882
2883         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2884                 return -EFAULT;
2885         return ret;
2886 }
2887
2888 #ifdef CONFIG_COMPAT
2889 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2890 {
2891         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2892 }
2893 #endif
2894
2895 static const struct file_operations pkt_ctl_fops = {
2896         .open           = nonseekable_open,
2897         .unlocked_ioctl = pkt_ctl_ioctl,
2898 #ifdef CONFIG_COMPAT
2899         .compat_ioctl   = pkt_ctl_compat_ioctl,
2900 #endif
2901         .owner          = THIS_MODULE,
2902         .llseek         = no_llseek,
2903 };
2904
2905 static struct miscdevice pkt_misc = {
2906         .minor          = MISC_DYNAMIC_MINOR,
2907         .name           = DRIVER_NAME,
2908         .nodename       = "pktcdvd/control",
2909         .fops           = &pkt_ctl_fops
2910 };
2911
2912 static int __init pkt_init(void)
2913 {
2914         int ret;
2915
2916         mutex_init(&ctl_mutex);
2917
2918         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2919                                         sizeof(struct packet_stacked_data));
2920         if (!psd_pool)
2921                 return -ENOMEM;
2922
2923         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2924         if (ret < 0) {
2925                 pr_err("unable to register block device\n");
2926                 goto out2;
2927         }
2928         if (!pktdev_major)
2929                 pktdev_major = ret;
2930
2931         ret = pkt_sysfs_init();
2932         if (ret)
2933                 goto out;
2934
2935         pkt_debugfs_init();
2936
2937         ret = misc_register(&pkt_misc);
2938         if (ret) {
2939                 pr_err("unable to register misc device\n");
2940                 goto out_misc;
2941         }
2942
2943         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2944
2945         return 0;
2946
2947 out_misc:
2948         pkt_debugfs_cleanup();
2949         pkt_sysfs_cleanup();
2950 out:
2951         unregister_blkdev(pktdev_major, DRIVER_NAME);
2952 out2:
2953         mempool_destroy(psd_pool);
2954         return ret;
2955 }
2956
2957 static void __exit pkt_exit(void)
2958 {
2959         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2960         misc_deregister(&pkt_misc);
2961
2962         pkt_debugfs_cleanup();
2963         pkt_sysfs_cleanup();
2964
2965         unregister_blkdev(pktdev_major, DRIVER_NAME);
2966         mempool_destroy(psd_pool);
2967 }
2968
2969 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2970 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2971 MODULE_LICENSE("GPL");
2972
2973 module_init(pkt_init);
2974 module_exit(pkt_exit);