drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <[email protected]>
   3  * Copyright (C) 2001-2004 Peter Osterlund <[email protected]>
   4  * Copyright (C) 2006 Thomas Maier <[email protected]>
   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 <asm/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 <[email protected]>
 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_WAIT);
 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_WAIT);
 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->cmd_flags |= REQ_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 /*
 948  * Copy all data for this packet to pkt->pages[], so that
 949  * a) The number of required segments for the write bio is minimized, which
 950  *    is necessary for some scsi controllers.
 951  * b) The data can be used as cache to avoid read requests if we receive a
 952  *    new write request for the same zone.
 953  */
 954 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
 955 {
 956         int f, p, offs;
 957
 958         /* Copy all data to pkt->pages[] */
 959         p = 0;
 960         offs = 0;
 961         for (f = 0; f < pkt->frames; f++) {
 962                 if (bvec[f].bv_page != pkt->pages[p]) {
 963                         void *vfrom = kmap_atomic(bvec[f].bv_page) + bvec[f].bv_offset;
 964                         void *vto = page_address(pkt->pages[p]) + offs;
 965                         memcpy(vto, vfrom, CD_FRAMESIZE);
 966                         kunmap_atomic(vfrom);
 967                         bvec[f].bv_page = pkt->pages[p];
 968                         bvec[f].bv_offset = offs;
 969                 } else {
 970                         BUG_ON(bvec[f].bv_offset != offs);
 971                 }
 972                 offs += CD_FRAMESIZE;
 973                 if (offs >= PAGE_SIZE) {
 974                         offs = 0;
 975                         p++;
 976                 }
 977         }
 978 }
 979
 980 static void pkt_end_io_read(struct bio *bio)
 981 {
 982         struct packet_data *pkt = bio->bi_private;
 983         struct pktcdvd_device *pd = pkt->pd;
 984         BUG_ON(!pd);
 985
 986         pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
 987                 bio, (unsigned long long)pkt->sector,
 988                 (unsigned long long)bio->bi_iter.bi_sector, bio->bi_error);
 989
 990         if (bio->bi_error)
 991                 atomic_inc(&pkt->io_errors);
 992         if (atomic_dec_and_test(&pkt->io_wait)) {
 993                 atomic_inc(&pkt->run_sm);
 994                 wake_up(&pd->wqueue);
 995         }
 996         pkt_bio_finished(pd);
 997 }
 998
 999 static void pkt_end_io_packet_write(struct bio *bio)
1000 {
1001         struct packet_data *pkt = bio->bi_private;
1002         struct pktcdvd_device *pd = pkt->pd;
1003         BUG_ON(!pd);
1004
1005         pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_error);
1006
1007         pd->stats.pkt_ended++;
1008
1009         pkt_bio_finished(pd);
1010         atomic_dec(&pkt->io_wait);
1011         atomic_inc(&pkt->run_sm);
1012         wake_up(&pd->wqueue);
1013 }
1014
1015 /*
1016  * Schedule reads for the holes in a packet
1017  */
1018 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1019 {
1020         int frames_read = 0;
1021         struct bio *bio;
1022         int f;
1023         char written[PACKET_MAX_SIZE];
1024
1025         BUG_ON(bio_list_empty(&pkt->orig_bios));
1026
1027         atomic_set(&pkt->io_wait, 0);
1028         atomic_set(&pkt->io_errors, 0);
1029
1030         /*
1031          * Figure out which frames we need to read before we can write.
1032          */
1033         memset(written, 0, sizeof(written));
1034         spin_lock(&pkt->lock);
1035         bio_list_for_each(bio, &pkt->orig_bios) {
1036                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1037                         (CD_FRAMESIZE >> 9);
1038                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1039                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1040                 BUG_ON(first_frame < 0);
1041                 BUG_ON(first_frame + num_frames > pkt->frames);
1042                 for (f = first_frame; f < first_frame + num_frames; f++)
1043                         written[f] = 1;
1044         }
1045         spin_unlock(&pkt->lock);
1046
1047         if (pkt->cache_valid) {
1048                 pkt_dbg(2, pd, "zone %llx cached\n",
1049                         (unsigned long long)pkt->sector);
1050                 goto out_account;
1051         }
1052
1053         /*
1054          * Schedule reads for missing parts of the packet.
1055          */
1056         for (f = 0; f < pkt->frames; f++) {
1057                 int p, offset;
1058
1059                 if (written[f])
1060                         continue;
1061
1062                 bio = pkt->r_bios[f];
1063                 bio_reset(bio);
1064                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1065                 bio->bi_bdev = pd->bdev;
1066                 bio->bi_end_io = pkt_end_io_read;
1067                 bio->bi_private = pkt;
1068
1069                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1070                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1071                 pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1072                         f, pkt->pages[p], offset);
1073                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1074                         BUG();
1075
1076                 atomic_inc(&pkt->io_wait);
1077                 bio->bi_rw = READ;
1078                 pkt_queue_bio(pd, bio);
1079                 frames_read++;
1080         }
1081
1082 out_account:
1083         pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1084                 frames_read, (unsigned long long)pkt->sector);
1085         pd->stats.pkt_started++;
1086         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1087 }
1088
1089 /*
1090  * Find a packet matching zone, or the least recently used packet if
1091  * there is no match.
1092  */
1093 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1094 {
1095         struct packet_data *pkt;
1096
1097         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1098                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1099                         list_del_init(&pkt->list);
1100                         if (pkt->sector != zone)
1101                                 pkt->cache_valid = 0;
1102                         return pkt;
1103                 }
1104         }
1105         BUG();
1106         return NULL;
1107 }
1108
1109 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1110 {
1111         if (pkt->cache_valid) {
1112                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1113         } else {
1114                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1115         }
1116 }
1117
1118 /*
1119  * recover a failed write, query for relocation if possible
1120  *
1121  * returns 1 if recovery is possible, or 0 if not
1122  *
1123  */
1124 static int pkt_start_recovery(struct packet_data *pkt)
1125 {
1126         /*
1127          * FIXME. We need help from the file system to implement
1128          * recovery handling.
1129          */
1130         return 0;
1131 #if 0
1132         struct request *rq = pkt->rq;
1133         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1134         struct block_device *pkt_bdev;
1135         struct super_block *sb = NULL;
1136         unsigned long old_block, new_block;
1137         sector_t new_sector;
1138
1139         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1140         if (pkt_bdev) {
1141                 sb = get_super(pkt_bdev);
1142                 bdput(pkt_bdev);
1143         }
1144
1145         if (!sb)
1146                 return 0;
1147
1148         if (!sb->s_op->relocate_blocks)
1149                 goto out;
1150
1151         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1152         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1153                 goto out;
1154
1155         new_sector = new_block * (CD_FRAMESIZE >> 9);
1156         pkt->sector = new_sector;
1157
1158         bio_reset(pkt->bio);
1159         pkt->bio->bi_bdev = pd->bdev;
1160         pkt->bio->bi_rw = REQ_WRITE;
1161         pkt->bio->bi_iter.bi_sector = new_sector;
1162         pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1163         pkt->bio->bi_vcnt = pkt->frames;
1164
1165         pkt->bio->bi_end_io = pkt_end_io_packet_write;
1166         pkt->bio->bi_private = pkt;
1167
1168         drop_super(sb);
1169         return 1;
1170
1171 out:
1172         drop_super(sb);
1173         return 0;
1174 #endif
1175 }
1176
1177 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1178 {
1179 #if PACKET_DEBUG > 1
1180         static const char *state_name[] = {
1181                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1182         };
1183         enum packet_data_state old_state = pkt->state;
1184         pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1185                 pkt->id, (unsigned long long)pkt->sector,
1186                 state_name[old_state], state_name[state]);
1187 #endif
1188         pkt->state = state;
1189 }
1190
1191 /*
1192  * Scan the work queue to see if we can start a new packet.
1193  * returns non-zero if any work was done.
1194  */
1195 static int pkt_handle_queue(struct pktcdvd_device *pd)
1196 {
1197         struct packet_data *pkt, *p;
1198         struct bio *bio = NULL;
1199         sector_t zone = 0; /* Suppress gcc warning */
1200         struct pkt_rb_node *node, *first_node;
1201         struct rb_node *n;
1202         int wakeup;
1203
1204         atomic_set(&pd->scan_queue, 0);
1205
1206         if (list_empty(&pd->cdrw.pkt_free_list)) {
1207                 pkt_dbg(2, pd, "no pkt\n");
1208                 return 0;
1209         }
1210
1211         /*
1212          * Try to find a zone we are not already working on.
1213          */
1214         spin_lock(&pd->lock);
1215         first_node = pkt_rbtree_find(pd, pd->current_sector);
1216         if (!first_node) {
1217                 n = rb_first(&pd->bio_queue);
1218                 if (n)
1219                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1220         }
1221         node = first_node;
1222         while (node) {
1223                 bio = node->bio;
1224                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1225                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1226                         if (p->sector == zone) {
1227                                 bio = NULL;
1228                                 goto try_next_bio;
1229                         }
1230                 }
1231                 break;
1232 try_next_bio:
1233                 node = pkt_rbtree_next(node);
1234                 if (!node) {
1235                         n = rb_first(&pd->bio_queue);
1236                         if (n)
1237                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1238                 }
1239                 if (node == first_node)
1240                         node = NULL;
1241         }
1242         spin_unlock(&pd->lock);
1243         if (!bio) {
1244                 pkt_dbg(2, pd, "no bio\n");
1245                 return 0;
1246         }
1247
1248         pkt = pkt_get_packet_data(pd, zone);
1249
1250         pd->current_sector = zone + pd->settings.size;
1251         pkt->sector = zone;
1252         BUG_ON(pkt->frames != pd->settings.size >> 2);
1253         pkt->write_size = 0;
1254
1255         /*
1256          * Scan work queue for bios in the same zone and link them
1257          * to this packet.
1258          */
1259         spin_lock(&pd->lock);
1260         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1261         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1262                 bio = node->bio;
1263                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1264                         get_zone(bio->bi_iter.bi_sector, pd));
1265                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1266                         break;
1267                 pkt_rbtree_erase(pd, node);
1268                 spin_lock(&pkt->lock);
1269                 bio_list_add(&pkt->orig_bios, bio);
1270                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1271                 spin_unlock(&pkt->lock);
1272         }
1273         /* check write congestion marks, and if bio_queue_size is
1274            below, wake up any waiters */
1275         wakeup = (pd->write_congestion_on > 0
1276                         && pd->bio_queue_size <= pd->write_congestion_off);
1277         spin_unlock(&pd->lock);
1278         if (wakeup) {
1279                 clear_bdi_congested(&pd->disk->queue->backing_dev_info,
1280                                         BLK_RW_ASYNC);
1281         }
1282
1283         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1284         pkt_set_state(pkt, PACKET_WAITING_STATE);
1285         atomic_set(&pkt->run_sm, 1);
1286
1287         spin_lock(&pd->cdrw.active_list_lock);
1288         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1289         spin_unlock(&pd->cdrw.active_list_lock);
1290
1291         return 1;
1292 }
1293
1294 /*
1295  * Assemble a bio to write one packet and queue the bio for processing
1296  * by the underlying block device.
1297  */
1298 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1299 {
1300         int f;
1301         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1302
1303         bio_reset(pkt->w_bio);
1304         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1305         pkt->w_bio->bi_bdev = pd->bdev;
1306         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1307         pkt->w_bio->bi_private = pkt;
1308
1309         /* XXX: locking? */
1310         for (f = 0; f < pkt->frames; f++) {
1311                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1312                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1313                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1314                         BUG();
1315         }
1316         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1317
1318         /*
1319          * Fill-in bvec with data from orig_bios.
1320          */
1321         spin_lock(&pkt->lock);
1322         bio_copy_data(pkt->w_bio, pkt->orig_bios.head);
1323
1324         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1325         spin_unlock(&pkt->lock);
1326
1327         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1328                 pkt->write_size, (unsigned long long)pkt->sector);
1329
1330         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1331                 pkt_make_local_copy(pkt, bvec);
1332                 pkt->cache_valid = 1;
1333         } else {
1334                 pkt->cache_valid = 0;
1335         }
1336
1337         /* Start the write request */
1338         atomic_set(&pkt->io_wait, 1);
1339         pkt->w_bio->bi_rw = WRITE;
1340         pkt_queue_bio(pd, pkt->w_bio);
1341 }
1342
1343 static void pkt_finish_packet(struct packet_data *pkt, int error)
1344 {
1345         struct bio *bio;
1346
1347         if (error)
1348                 pkt->cache_valid = 0;
1349
1350         /* Finish all bios corresponding to this packet */
1351         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1352                 bio->bi_error = error;
1353                 bio_endio(bio);
1354         }
1355 }
1356
1357 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1358 {
1359         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1360
1361         for (;;) {
1362                 switch (pkt->state) {
1363                 case PACKET_WAITING_STATE:
1364                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1365                                 return;
1366
1367                         pkt->sleep_time = 0;
1368                         pkt_gather_data(pd, pkt);
1369                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1370                         break;
1371
1372                 case PACKET_READ_WAIT_STATE:
1373                         if (atomic_read(&pkt->io_wait) > 0)
1374                                 return;
1375
1376                         if (atomic_read(&pkt->io_errors) > 0) {
1377                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1378                         } else {
1379                                 pkt_start_write(pd, pkt);
1380                         }
1381                         break;
1382
1383                 case PACKET_WRITE_WAIT_STATE:
1384                         if (atomic_read(&pkt->io_wait) > 0)
1385                                 return;
1386
1387                         if (!pkt->w_bio->bi_error) {
1388                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1389                         } else {
1390                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1391                         }
1392                         break;
1393
1394                 case PACKET_RECOVERY_STATE:
1395                         if (pkt_start_recovery(pkt)) {
1396                                 pkt_start_write(pd, pkt);
1397                         } else {
1398                                 pkt_dbg(2, pd, "No recovery possible\n");
1399                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1400                         }
1401                         break;
1402
1403                 case PACKET_FINISHED_STATE:
1404                         pkt_finish_packet(pkt, pkt->w_bio->bi_error);
1405                         return;
1406
1407                 default:
1408                         BUG();
1409                         break;
1410                 }
1411         }
1412 }
1413
1414 static void pkt_handle_packets(struct pktcdvd_device *pd)
1415 {
1416         struct packet_data *pkt, *next;
1417
1418         /*
1419          * Run state machine for active packets
1420          */
1421         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1422                 if (atomic_read(&pkt->run_sm) > 0) {
1423                         atomic_set(&pkt->run_sm, 0);
1424                         pkt_run_state_machine(pd, pkt);
1425                 }
1426         }
1427
1428         /*
1429          * Move no longer active packets to the free list
1430          */
1431         spin_lock(&pd->cdrw.active_list_lock);
1432         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1433                 if (pkt->state == PACKET_FINISHED_STATE) {
1434                         list_del(&pkt->list);
1435                         pkt_put_packet_data(pd, pkt);
1436                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1437                         atomic_set(&pd->scan_queue, 1);
1438                 }
1439         }
1440         spin_unlock(&pd->cdrw.active_list_lock);
1441 }
1442
1443 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1444 {
1445         struct packet_data *pkt;
1446         int i;
1447
1448         for (i = 0; i < PACKET_NUM_STATES; i++)
1449                 states[i] = 0;
1450
1451         spin_lock(&pd->cdrw.active_list_lock);
1452         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1453                 states[pkt->state]++;
1454         }
1455         spin_unlock(&pd->cdrw.active_list_lock);
1456 }
1457
1458 /*
1459  * kcdrwd is woken up when writes have been queued for one of our
1460  * registered devices
1461  */
1462 static int kcdrwd(void *foobar)
1463 {
1464         struct pktcdvd_device *pd = foobar;
1465         struct packet_data *pkt;
1466         long min_sleep_time, residue;
1467
1468         set_user_nice(current, MIN_NICE);
1469         set_freezable();
1470
1471         for (;;) {
1472                 DECLARE_WAITQUEUE(wait, current);
1473
1474                 /*
1475                  * Wait until there is something to do
1476                  */
1477                 add_wait_queue(&pd->wqueue, &wait);
1478                 for (;;) {
1479                         set_current_state(TASK_INTERRUPTIBLE);
1480
1481                         /* Check if we need to run pkt_handle_queue */
1482                         if (atomic_read(&pd->scan_queue) > 0)
1483                                 goto work_to_do;
1484
1485                         /* Check if we need to run the state machine for some packet */
1486                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1487                                 if (atomic_read(&pkt->run_sm) > 0)
1488                                         goto work_to_do;
1489                         }
1490
1491                         /* Check if we need to process the iosched queues */
1492                         if (atomic_read(&pd->iosched.attention) != 0)
1493                                 goto work_to_do;
1494
1495                         /* Otherwise, go to sleep */
1496                         if (PACKET_DEBUG > 1) {
1497                                 int states[PACKET_NUM_STATES];
1498                                 pkt_count_states(pd, states);
1499                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1500                                         states[0], states[1], states[2],
1501                                         states[3], states[4], states[5]);
1502                         }
1503
1504                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1505                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1506                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1507                                         min_sleep_time = pkt->sleep_time;
1508                         }
1509
1510                         pkt_dbg(2, pd, "sleeping\n");
1511                         residue = schedule_timeout(min_sleep_time);
1512                         pkt_dbg(2, pd, "wake up\n");
1513
1514                         /* make swsusp happy with our thread */
1515                         try_to_freeze();
1516
1517                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1518                                 if (!pkt->sleep_time)
1519                                         continue;
1520                                 pkt->sleep_time -= min_sleep_time - residue;
1521                                 if (pkt->sleep_time <= 0) {
1522                                         pkt->sleep_time = 0;
1523                                         atomic_inc(&pkt->run_sm);
1524                                 }
1525                         }
1526
1527                         if (kthread_should_stop())
1528                                 break;
1529                 }
1530 work_to_do:
1531                 set_current_state(TASK_RUNNING);
1532                 remove_wait_queue(&pd->wqueue, &wait);
1533
1534                 if (kthread_should_stop())
1535                         break;
1536
1537                 /*
1538                  * if pkt_handle_queue returns true, we can queue
1539                  * another request.
1540                  */
1541                 while (pkt_handle_queue(pd))
1542                         ;
1543
1544                 /*
1545                  * Handle packet state machine
1546                  */
1547                 pkt_handle_packets(pd);
1548
1549                 /*
1550                  * Handle iosched queues
1551                  */
1552                 pkt_iosched_process_queue(pd);
1553         }
1554
1555         return 0;
1556 }
1557
1558 static void pkt_print_settings(struct pktcdvd_device *pd)
1559 {
1560         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1561                  pd->settings.fp ? "Fixed" : "Variable",
1562                  pd->settings.size >> 2,
1563                  pd->settings.block_mode == 8 ? '1' : '2');
1564 }
1565
1566 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1567 {
1568         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1569
1570         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1571         cgc->cmd[2] = page_code | (page_control << 6);
1572         cgc->cmd[7] = cgc->buflen >> 8;
1573         cgc->cmd[8] = cgc->buflen & 0xff;
1574         cgc->data_direction = CGC_DATA_READ;
1575         return pkt_generic_packet(pd, cgc);
1576 }
1577
1578 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1579 {
1580         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1581         memset(cgc->buffer, 0, 2);
1582         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1583         cgc->cmd[1] = 0x10;             /* PF */
1584         cgc->cmd[7] = cgc->buflen >> 8;
1585         cgc->cmd[8] = cgc->buflen & 0xff;
1586         cgc->data_direction = CGC_DATA_WRITE;
1587         return pkt_generic_packet(pd, cgc);
1588 }
1589
1590 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1591 {
1592         struct packet_command cgc;
1593         int ret;
1594
1595         /* set up command and get the disc info */
1596         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1597         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1598         cgc.cmd[8] = cgc.buflen = 2;
1599         cgc.quiet = 1;
1600
1601         if ((ret = pkt_generic_packet(pd, &cgc)))
1602                 return ret;
1603
1604         /* not all drives have the same disc_info length, so requeue
1605          * packet with the length the drive tells us it can supply
1606          */
1607         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1608                      sizeof(di->disc_information_length);
1609
1610         if (cgc.buflen > sizeof(disc_information))
1611                 cgc.buflen = sizeof(disc_information);
1612
1613         cgc.cmd[8] = cgc.buflen;
1614         return pkt_generic_packet(pd, &cgc);
1615 }
1616
1617 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1618 {
1619         struct packet_command cgc;
1620         int ret;
1621
1622         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1623         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1624         cgc.cmd[1] = type & 3;
1625         cgc.cmd[4] = (track & 0xff00) >> 8;
1626         cgc.cmd[5] = track & 0xff;
1627         cgc.cmd[8] = 8;
1628         cgc.quiet = 1;
1629
1630         if ((ret = pkt_generic_packet(pd, &cgc)))
1631                 return ret;
1632
1633         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1634                      sizeof(ti->track_information_length);
1635
1636         if (cgc.buflen > sizeof(track_information))
1637                 cgc.buflen = sizeof(track_information);
1638
1639         cgc.cmd[8] = cgc.buflen;
1640         return pkt_generic_packet(pd, &cgc);
1641 }
1642
1643 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1644                                                 long *last_written)
1645 {
1646         disc_information di;
1647         track_information ti;
1648         __u32 last_track;
1649         int ret = -1;
1650
1651         if ((ret = pkt_get_disc_info(pd, &di)))
1652                 return ret;
1653
1654         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1655         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1656                 return ret;
1657
1658         /* if this track is blank, try the previous. */
1659         if (ti.blank) {
1660                 last_track--;
1661                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1662                         return ret;
1663         }
1664
1665         /* if last recorded field is valid, return it. */
1666         if (ti.lra_v) {
1667                 *last_written = be32_to_cpu(ti.last_rec_address);
1668         } else {
1669                 /* make it up instead */
1670                 *last_written = be32_to_cpu(ti.track_start) +
1671                                 be32_to_cpu(ti.track_size);
1672                 if (ti.free_blocks)
1673                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1674         }
1675         return 0;
1676 }
1677
1678 /*
1679  * write mode select package based on pd->settings
1680  */
1681 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1682 {
1683         struct packet_command cgc;
1684         struct request_sense sense;
1685         write_param_page *wp;
1686         char buffer[128];
1687         int ret, size;
1688
1689         /* doesn't apply to DVD+RW or DVD-RAM */
1690         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1691                 return 0;
1692
1693         memset(buffer, 0, sizeof(buffer));
1694         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1695         cgc.sense = &sense;
1696         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1697                 pkt_dump_sense(pd, &cgc);
1698                 return ret;
1699         }
1700
1701         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1702         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1703         if (size > sizeof(buffer))
1704                 size = sizeof(buffer);
1705
1706         /*
1707          * now get it all
1708          */
1709         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1710         cgc.sense = &sense;
1711         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1712                 pkt_dump_sense(pd, &cgc);
1713                 return ret;
1714         }
1715
1716         /*
1717          * write page is offset header + block descriptor length
1718          */
1719         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1720
1721         wp->fp = pd->settings.fp;
1722         wp->track_mode = pd->settings.track_mode;
1723         wp->write_type = pd->settings.write_type;
1724         wp->data_block_type = pd->settings.block_mode;
1725
1726         wp->multi_session = 0;
1727
1728 #ifdef PACKET_USE_LS
1729         wp->link_size = 7;
1730         wp->ls_v = 1;
1731 #endif
1732
1733         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1734                 wp->session_format = 0;
1735                 wp->subhdr2 = 0x20;
1736         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1737                 wp->session_format = 0x20;
1738                 wp->subhdr2 = 8;
1739 #if 0
1740                 wp->mcn[0] = 0x80;
1741                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1742 #endif
1743         } else {
1744                 /*
1745                  * paranoia
1746                  */
1747                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1748                 return 1;
1749         }
1750         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1751
1752         cgc.buflen = cgc.cmd[8] = size;
1753         if ((ret = pkt_mode_select(pd, &cgc))) {
1754                 pkt_dump_sense(pd, &cgc);
1755                 return ret;
1756         }
1757
1758         pkt_print_settings(pd);
1759         return 0;
1760 }
1761
1762 /*
1763  * 1 -- we can write to this track, 0 -- we can't
1764  */
1765 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1766 {
1767         switch (pd->mmc3_profile) {
1768                 case 0x1a: /* DVD+RW */
1769                 case 0x12: /* DVD-RAM */
1770                         /* The track is always writable on DVD+RW/DVD-RAM */
1771                         return 1;
1772                 default:
1773                         break;
1774         }
1775
1776         if (!ti->packet || !ti->fp)
1777                 return 0;
1778
1779         /*
1780          * "good" settings as per Mt Fuji.
1781          */
1782         if (ti->rt == 0 && ti->blank == 0)
1783                 return 1;
1784
1785         if (ti->rt == 0 && ti->blank == 1)
1786                 return 1;
1787
1788         if (ti->rt == 1 && ti->blank == 0)
1789                 return 1;
1790
1791         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1792         return 0;
1793 }
1794
1795 /*
1796  * 1 -- we can write to this disc, 0 -- we can't
1797  */
1798 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1799 {
1800         switch (pd->mmc3_profile) {
1801                 case 0x0a: /* CD-RW */
1802                 case 0xffff: /* MMC3 not supported */
1803                         break;
1804                 case 0x1a: /* DVD+RW */
1805                 case 0x13: /* DVD-RW */
1806                 case 0x12: /* DVD-RAM */
1807                         return 1;
1808                 default:
1809                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1810                                 pd->mmc3_profile);
1811                         return 0;
1812         }
1813
1814         /*
1815          * for disc type 0xff we should probably reserve a new track.
1816          * but i'm not sure, should we leave this to user apps? probably.
1817          */
1818         if (di->disc_type == 0xff) {
1819                 pkt_notice(pd, "unknown disc - no track?\n");
1820                 return 0;
1821         }
1822
1823         if (di->disc_type != 0x20 && di->disc_type != 0) {
1824                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1825                 return 0;
1826         }
1827
1828         if (di->erasable == 0) {
1829                 pkt_notice(pd, "disc not erasable\n");
1830                 return 0;
1831         }
1832
1833         if (di->border_status == PACKET_SESSION_RESERVED) {
1834                 pkt_err(pd, "can't write to last track (reserved)\n");
1835                 return 0;
1836         }
1837
1838         return 1;
1839 }
1840
1841 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1842 {
1843         struct packet_command cgc;
1844         unsigned char buf[12];
1845         disc_information di;
1846         track_information ti;
1847         int ret, track;
1848
1849         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1850         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1851         cgc.cmd[8] = 8;
1852         ret = pkt_generic_packet(pd, &cgc);
1853         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1854
1855         memset(&di, 0, sizeof(disc_information));
1856         memset(&ti, 0, sizeof(track_information));
1857
1858         if ((ret = pkt_get_disc_info(pd, &di))) {
1859                 pkt_err(pd, "failed get_disc\n");
1860                 return ret;
1861         }
1862
1863         if (!pkt_writable_disc(pd, &di))
1864                 return -EROFS;
1865
1866         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1867
1868         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1869         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1870                 pkt_err(pd, "failed get_track\n");
1871                 return ret;
1872         }
1873
1874         if (!pkt_writable_track(pd, &ti)) {
1875                 pkt_err(pd, "can't write to this track\n");
1876                 return -EROFS;
1877         }
1878
1879         /*
1880          * we keep packet size in 512 byte units, makes it easier to
1881          * deal with request calculations.
1882          */
1883         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1884         if (pd->settings.size == 0) {
1885                 pkt_notice(pd, "detected zero packet size!\n");
1886                 return -ENXIO;
1887         }
1888         if (pd->settings.size > PACKET_MAX_SECTORS) {
1889                 pkt_err(pd, "packet size is too big\n");
1890                 return -EROFS;
1891         }
1892         pd->settings.fp = ti.fp;
1893         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1894
1895         if (ti.nwa_v) {
1896                 pd->nwa = be32_to_cpu(ti.next_writable);
1897                 set_bit(PACKET_NWA_VALID, &pd->flags);
1898         }
1899
1900         /*
1901          * in theory we could use lra on -RW media as well and just zero
1902          * blocks that haven't been written yet, but in practice that
1903          * is just a no-go. we'll use that for -R, naturally.
1904          */
1905         if (ti.lra_v) {
1906                 pd->lra = be32_to_cpu(ti.last_rec_address);
1907                 set_bit(PACKET_LRA_VALID, &pd->flags);
1908         } else {
1909                 pd->lra = 0xffffffff;
1910                 set_bit(PACKET_LRA_VALID, &pd->flags);
1911         }
1912
1913         /*
1914          * fine for now
1915          */
1916         pd->settings.link_loss = 7;
1917         pd->settings.write_type = 0;    /* packet */
1918         pd->settings.track_mode = ti.track_mode;
1919
1920         /*
1921          * mode1 or mode2 disc
1922          */
1923         switch (ti.data_mode) {
1924                 case PACKET_MODE1:
1925                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1926                         break;
1927                 case PACKET_MODE2:
1928                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1929                         break;
1930                 default:
1931                         pkt_err(pd, "unknown data mode\n");
1932                         return -EROFS;
1933         }
1934         return 0;
1935 }
1936
1937 /*
1938  * enable/disable write caching on drive
1939  */
1940 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1941                                                 int set)
1942 {
1943         struct packet_command cgc;
1944         struct request_sense sense;
1945         unsigned char buf[64];
1946         int ret;
1947
1948         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1949         cgc.sense = &sense;
1950         cgc.buflen = pd->mode_offset + 12;
1951
1952         /*
1953          * caching mode page might not be there, so quiet this command
1954          */
1955         cgc.quiet = 1;
1956
1957         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1958                 return ret;
1959
1960         buf[pd->mode_offset + 10] |= (!!set << 2);
1961
1962         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1963         ret = pkt_mode_select(pd, &cgc);
1964         if (ret) {
1965                 pkt_err(pd, "write caching control failed\n");
1966                 pkt_dump_sense(pd, &cgc);
1967         } else if (!ret && set)
1968                 pkt_notice(pd, "enabled write caching\n");
1969         return ret;
1970 }
1971
1972 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1973 {
1974         struct packet_command cgc;
1975
1976         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1977         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1978         cgc.cmd[4] = lockflag ? 1 : 0;
1979         return pkt_generic_packet(pd, &cgc);
1980 }
1981
1982 /*
1983  * Returns drive maximum write speed
1984  */
1985 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1986                                                 unsigned *write_speed)
1987 {
1988         struct packet_command cgc;
1989         struct request_sense sense;
1990         unsigned char buf[256+18];
1991         unsigned char *cap_buf;
1992         int ret, offset;
1993
1994         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1995         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1996         cgc.sense = &sense;
1997
1998         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1999         if (ret) {
2000                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2001                              sizeof(struct mode_page_header);
2002                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2003                 if (ret) {
2004                         pkt_dump_sense(pd, &cgc);
2005                         return ret;
2006                 }
2007         }
2008
2009         offset = 20;                        /* Obsoleted field, used by older drives */
2010         if (cap_buf[1] >= 28)
2011                 offset = 28;                /* Current write speed selected */
2012         if (cap_buf[1] >= 30) {
2013                 /* If the drive reports at least one "Logical Unit Write
2014                  * Speed Performance Descriptor Block", use the information
2015                  * in the first block. (contains the highest speed)
2016                  */
2017                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2018                 if (num_spdb > 0)
2019                         offset = 34;
2020         }
2021
2022         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2023         return 0;
2024 }
2025
2026 /* These tables from cdrecord - I don't have orange book */
2027 /* standard speed CD-RW (1-4x) */
2028 static char clv_to_speed[16] = {
2029         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2030            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2031 };
2032 /* high speed CD-RW (-10x) */
2033 static char hs_clv_to_speed[16] = {
2034         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2035            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2036 };
2037 /* ultra high speed CD-RW */
2038 static char us_clv_to_speed[16] = {
2039         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2040            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2041 };
2042
2043 /*
2044  * reads the maximum media speed from ATIP
2045  */
2046 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2047                                                 unsigned *speed)
2048 {
2049         struct packet_command cgc;
2050         struct request_sense sense;
2051         unsigned char buf[64];
2052         unsigned int size, st, sp;
2053         int ret;
2054
2055         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2056         cgc.sense = &sense;
2057         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2058         cgc.cmd[1] = 2;
2059         cgc.cmd[2] = 4; /* READ ATIP */
2060         cgc.cmd[8] = 2;
2061         ret = pkt_generic_packet(pd, &cgc);
2062         if (ret) {
2063                 pkt_dump_sense(pd, &cgc);
2064                 return ret;
2065         }
2066         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2067         if (size > sizeof(buf))
2068                 size = sizeof(buf);
2069
2070         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2071         cgc.sense = &sense;
2072         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2073         cgc.cmd[1] = 2;
2074         cgc.cmd[2] = 4;
2075         cgc.cmd[8] = size;
2076         ret = pkt_generic_packet(pd, &cgc);
2077         if (ret) {
2078                 pkt_dump_sense(pd, &cgc);
2079                 return ret;
2080         }
2081
2082         if (!(buf[6] & 0x40)) {
2083                 pkt_notice(pd, "disc type is not CD-RW\n");
2084                 return 1;
2085         }
2086         if (!(buf[6] & 0x4)) {
2087                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2088                 return 1;
2089         }
2090
2091         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2092
2093         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2094
2095         /* Info from cdrecord */
2096         switch (st) {
2097                 case 0: /* standard speed */
2098                         *speed = clv_to_speed[sp];
2099                         break;
2100                 case 1: /* high speed */
2101                         *speed = hs_clv_to_speed[sp];
2102                         break;
2103                 case 2: /* ultra high speed */
2104                         *speed = us_clv_to_speed[sp];
2105                         break;
2106                 default:
2107                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2108                         return 1;
2109         }
2110         if (*speed) {
2111                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2112                 return 0;
2113         } else {
2114                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2115                 return 1;
2116         }
2117 }
2118
2119 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2120 {
2121         struct packet_command cgc;
2122         struct request_sense sense;
2123         int ret;
2124
2125         pkt_dbg(2, pd, "Performing OPC\n");
2126
2127         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2128         cgc.sense = &sense;
2129         cgc.timeout = 60*HZ;
2130         cgc.cmd[0] = GPCMD_SEND_OPC;
2131         cgc.cmd[1] = 1;
2132         if ((ret = pkt_generic_packet(pd, &cgc)))
2133                 pkt_dump_sense(pd, &cgc);
2134         return ret;
2135 }
2136
2137 static int pkt_open_write(struct pktcdvd_device *pd)
2138 {
2139         int ret;
2140         unsigned int write_speed, media_write_speed, read_speed;
2141
2142         if ((ret = pkt_probe_settings(pd))) {
2143                 pkt_dbg(2, pd, "failed probe\n");
2144                 return ret;
2145         }
2146
2147         if ((ret = pkt_set_write_settings(pd))) {
2148                 pkt_dbg(1, pd, "failed saving write settings\n");
2149                 return -EIO;
2150         }
2151
2152         pkt_write_caching(pd, USE_WCACHING);
2153
2154         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2155                 write_speed = 16 * 177;
2156         switch (pd->mmc3_profile) {
2157                 case 0x13: /* DVD-RW */
2158                 case 0x1a: /* DVD+RW */
2159                 case 0x12: /* DVD-RAM */
2160                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2161                         break;
2162                 default:
2163                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2164                                 media_write_speed = 16;
2165                         write_speed = min(write_speed, media_write_speed * 177);
2166                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2167                         break;
2168         }
2169         read_speed = write_speed;
2170
2171         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2172                 pkt_dbg(1, pd, "couldn't set write speed\n");
2173                 return -EIO;
2174         }
2175         pd->write_speed = write_speed;
2176         pd->read_speed = read_speed;
2177
2178         if ((ret = pkt_perform_opc(pd))) {
2179                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2180         }
2181
2182         return 0;
2183 }
2184
2185 /*
2186  * called at open time.
2187  */
2188 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2189 {
2190         int ret;
2191         long lba;
2192         struct request_queue *q;
2193
2194         /*
2195          * We need to re-open the cdrom device without O_NONBLOCK to be able
2196          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2197          * so bdget() can't fail.
2198          */
2199         bdget(pd->bdev->bd_dev);
2200         if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2201                 goto out;
2202
2203         if ((ret = pkt_get_last_written(pd, &lba))) {
2204                 pkt_err(pd, "pkt_get_last_written failed\n");
2205                 goto out_putdev;
2206         }
2207
2208         set_capacity(pd->disk, lba << 2);
2209         set_capacity(pd->bdev->bd_disk, lba << 2);
2210         bd_set_size(pd->bdev, (loff_t)lba << 11);
2211
2212         q = bdev_get_queue(pd->bdev);
2213         if (write) {
2214                 if ((ret = pkt_open_write(pd)))
2215                         goto out_putdev;
2216                 /*
2217                  * Some CDRW drives can not handle writes larger than one packet,
2218                  * even if the size is a multiple of the packet size.
2219                  */
2220                 spin_lock_irq(q->queue_lock);
2221                 blk_queue_max_hw_sectors(q, pd->settings.size);
2222                 spin_unlock_irq(q->queue_lock);
2223                 set_bit(PACKET_WRITABLE, &pd->flags);
2224         } else {
2225                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2226                 clear_bit(PACKET_WRITABLE, &pd->flags);
2227         }
2228
2229         if ((ret = pkt_set_segment_merging(pd, q)))
2230                 goto out_putdev;
2231
2232         if (write) {
2233                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2234                         pkt_err(pd, "not enough memory for buffers\n");
2235                         ret = -ENOMEM;
2236                         goto out_putdev;
2237                 }
2238                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2239         }
2240
2241         return 0;
2242
2243 out_putdev:
2244         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2245 out:
2246         return ret;
2247 }
2248
2249 /*
2250  * called when the device is closed. makes sure that the device flushes
2251  * the internal cache before we close.
2252  */
2253 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2254 {
2255         if (flush && pkt_flush_cache(pd))
2256                 pkt_dbg(1, pd, "not flushing cache\n");
2257
2258         pkt_lock_door(pd, 0);
2259
2260         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2261         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2262
2263         pkt_shrink_pktlist(pd);
2264 }
2265
2266 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2267 {
2268         if (dev_minor >= MAX_WRITERS)
2269                 return NULL;
2270         return pkt_devs[dev_minor];
2271 }
2272
2273 static int pkt_open(struct block_device *bdev, fmode_t mode)
2274 {
2275         struct pktcdvd_device *pd = NULL;
2276         int ret;
2277
2278         mutex_lock(&pktcdvd_mutex);
2279         mutex_lock(&ctl_mutex);
2280         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2281         if (!pd) {
2282                 ret = -ENODEV;
2283                 goto out;
2284         }
2285         BUG_ON(pd->refcnt < 0);
2286
2287         pd->refcnt++;
2288         if (pd->refcnt > 1) {
2289                 if ((mode & FMODE_WRITE) &&
2290                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2291                         ret = -EBUSY;
2292                         goto out_dec;
2293                 }
2294         } else {
2295                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2296                 if (ret)
2297                         goto out_dec;
2298                 /*
2299                  * needed here as well, since ext2 (among others) may change
2300                  * the blocksize at mount time
2301                  */
2302                 set_blocksize(bdev, CD_FRAMESIZE);
2303         }
2304
2305         mutex_unlock(&ctl_mutex);
2306         mutex_unlock(&pktcdvd_mutex);
2307         return 0;
2308
2309 out_dec:
2310         pd->refcnt--;
2311 out:
2312         mutex_unlock(&ctl_mutex);
2313         mutex_unlock(&pktcdvd_mutex);
2314         return ret;
2315 }
2316
2317 static void pkt_close(struct gendisk *disk, fmode_t mode)
2318 {
2319         struct pktcdvd_device *pd = disk->private_data;
2320
2321         mutex_lock(&pktcdvd_mutex);
2322         mutex_lock(&ctl_mutex);
2323         pd->refcnt--;
2324         BUG_ON(pd->refcnt < 0);
2325         if (pd->refcnt == 0) {
2326                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2327                 pkt_release_dev(pd, flush);
2328         }
2329         mutex_unlock(&ctl_mutex);
2330         mutex_unlock(&pktcdvd_mutex);
2331 }
2332
2333
2334 static void pkt_end_io_read_cloned(struct bio *bio)
2335 {
2336         struct packet_stacked_data *psd = bio->bi_private;
2337         struct pktcdvd_device *pd = psd->pd;
2338
2339         psd->bio->bi_error = bio->bi_error;
2340         bio_put(bio);
2341         bio_endio(psd->bio);
2342         mempool_free(psd, psd_pool);
2343         pkt_bio_finished(pd);
2344 }
2345
2346 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2347 {
2348         struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2349         struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2350
2351         psd->pd = pd;
2352         psd->bio = bio;
2353         cloned_bio->bi_bdev = pd->bdev;
2354         cloned_bio->bi_private = psd;
2355         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2356         pd->stats.secs_r += bio_sectors(bio);
2357         pkt_queue_bio(pd, cloned_bio);
2358 }
2359
2360 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2361 {
2362         struct pktcdvd_device *pd = q->queuedata;
2363         sector_t zone;
2364         struct packet_data *pkt;
2365         int was_empty, blocked_bio;
2366         struct pkt_rb_node *node;
2367
2368         zone = get_zone(bio->bi_iter.bi_sector, pd);
2369
2370         /*
2371          * If we find a matching packet in state WAITING or READ_WAIT, we can
2372          * just append this bio to that packet.
2373          */
2374         spin_lock(&pd->cdrw.active_list_lock);
2375         blocked_bio = 0;
2376         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2377                 if (pkt->sector == zone) {
2378                         spin_lock(&pkt->lock);
2379                         if ((pkt->state == PACKET_WAITING_STATE) ||
2380                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2381                                 bio_list_add(&pkt->orig_bios, bio);
2382                                 pkt->write_size +=
2383                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2384                                 if ((pkt->write_size >= pkt->frames) &&
2385                                     (pkt->state == PACKET_WAITING_STATE)) {
2386                                         atomic_inc(&pkt->run_sm);
2387                                         wake_up(&pd->wqueue);
2388                                 }
2389                                 spin_unlock(&pkt->lock);
2390                                 spin_unlock(&pd->cdrw.active_list_lock);
2391                                 return;
2392                         } else {
2393                                 blocked_bio = 1;
2394                         }
2395                         spin_unlock(&pkt->lock);
2396                 }
2397         }
2398         spin_unlock(&pd->cdrw.active_list_lock);
2399
2400         /*
2401          * Test if there is enough room left in the bio work queue
2402          * (queue size >= congestion on mark).
2403          * If not, wait till the work queue size is below the congestion off mark.
2404          */
2405         spin_lock(&pd->lock);
2406         if (pd->write_congestion_on > 0
2407             && pd->bio_queue_size >= pd->write_congestion_on) {
2408                 set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2409                 do {
2410                         spin_unlock(&pd->lock);
2411                         congestion_wait(BLK_RW_ASYNC, HZ);
2412                         spin_lock(&pd->lock);
2413                 } while(pd->bio_queue_size > pd->write_congestion_off);
2414         }
2415         spin_unlock(&pd->lock);
2416
2417         /*
2418          * No matching packet found. Store the bio in the work queue.
2419          */
2420         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2421         node->bio = bio;
2422         spin_lock(&pd->lock);
2423         BUG_ON(pd->bio_queue_size < 0);
2424         was_empty = (pd->bio_queue_size == 0);
2425         pkt_rbtree_insert(pd, node);
2426         spin_unlock(&pd->lock);
2427
2428         /*
2429          * Wake up the worker thread.
2430          */
2431         atomic_set(&pd->scan_queue, 1);
2432         if (was_empty) {
2433                 /* This wake_up is required for correct operation */
2434                 wake_up(&pd->wqueue);
2435         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2436                 /*
2437                  * This wake up is not required for correct operation,
2438                  * but improves performance in some cases.
2439                  */
2440                 wake_up(&pd->wqueue);
2441         }
2442 }
2443
2444 static void pkt_make_request(struct request_queue *q, struct bio *bio)
2445 {
2446         struct pktcdvd_device *pd;
2447         char b[BDEVNAME_SIZE];
2448         struct bio *split;
2449
2450         pd = q->queuedata;
2451         if (!pd) {
2452                 pr_err("%s incorrect request queue\n",
2453                        bdevname(bio->bi_bdev, b));
2454                 goto end_io;
2455         }
2456
2457         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2458                 (unsigned long long)bio->bi_iter.bi_sector,
2459                 (unsigned long long)bio_end_sector(bio));
2460
2461         /*
2462          * Clone READ bios so we can have our own bi_end_io callback.
2463          */
2464         if (bio_data_dir(bio) == READ) {
2465                 pkt_make_request_read(pd, bio);
2466                 return;
2467         }
2468
2469         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2470                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2471                            (unsigned long long)bio->bi_iter.bi_sector);
2472                 goto end_io;
2473         }
2474
2475         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2476                 pkt_err(pd, "wrong bio size\n");
2477                 goto end_io;
2478         }
2479
2480         blk_queue_bounce(q, &bio);
2481
2482         do {
2483                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2484                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2485
2486                 if (last_zone != zone) {
2487                         BUG_ON(last_zone != zone + pd->settings.size);
2488
2489                         split = bio_split(bio, last_zone -
2490                                           bio->bi_iter.bi_sector,
2491                                           GFP_NOIO, fs_bio_set);
2492                         bio_chain(split, bio);
2493                 } else {
2494                         split = bio;
2495                 }
2496
2497                 pkt_make_request_write(q, split);
2498         } while (split != bio);
2499
2500         return;
2501 end_io:
2502         bio_io_error(bio);
2503 }
2504
2505
2506
2507 static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2508                           struct bio_vec *bvec)
2509 {
2510         struct pktcdvd_device *pd = q->queuedata;
2511         sector_t zone = get_zone(bmd->bi_sector, pd);
2512         int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
2513         int remaining = (pd->settings.size << 9) - used;
2514         int remaining2;
2515
2516         /*
2517          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2518          * boundary, pkt_make_request() will split the bio.
2519          */
2520         remaining2 = PAGE_SIZE - bmd->bi_size;
2521         remaining = max(remaining, remaining2);
2522
2523         BUG_ON(remaining < 0);
2524         return remaining;
2525 }
2526
2527 static void pkt_init_queue(struct pktcdvd_device *pd)
2528 {
2529         struct request_queue *q = pd->disk->queue;
2530
2531         blk_queue_make_request(q, pkt_make_request);
2532         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2533         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2534         blk_queue_merge_bvec(q, pkt_merge_bvec);
2535         q->queuedata = pd;
2536 }
2537
2538 static int pkt_seq_show(struct seq_file *m, void *p)
2539 {
2540         struct pktcdvd_device *pd = m->private;
2541         char *msg;
2542         char bdev_buf[BDEVNAME_SIZE];
2543         int states[PACKET_NUM_STATES];
2544
2545         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2546                    bdevname(pd->bdev, bdev_buf));
2547
2548         seq_printf(m, "\nSettings:\n");
2549         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2550
2551         if (pd->settings.write_type == 0)
2552                 msg = "Packet";
2553         else
2554                 msg = "Unknown";
2555         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2556
2557         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2558         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2559
2560         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2561
2562         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2563                 msg = "Mode 1";
2564         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2565                 msg = "Mode 2";
2566         else
2567                 msg = "Unknown";
2568         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2569
2570         seq_printf(m, "\nStatistics:\n");
2571         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2572         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2573         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2574         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2575         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2576
2577         seq_printf(m, "\nMisc:\n");
2578         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2579         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2580         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2581         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2582         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2583         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2584
2585         seq_printf(m, "\nQueue state:\n");
2586         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2587         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2588         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2589
2590         pkt_count_states(pd, states);
2591         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2592                    states[0], states[1], states[2], states[3], states[4], states[5]);
2593
2594         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2595                         pd->write_congestion_off,
2596                         pd->write_congestion_on);
2597         return 0;
2598 }
2599
2600 static int pkt_seq_open(struct inode *inode, struct file *file)
2601 {
2602         return single_open(file, pkt_seq_show, PDE_DATA(inode));
2603 }
2604
2605 static const struct file_operations pkt_proc_fops = {
2606         .open   = pkt_seq_open,
2607         .read   = seq_read,
2608         .llseek = seq_lseek,
2609         .release = single_release
2610 };
2611
2612 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2613 {
2614         int i;
2615         int ret = 0;
2616         char b[BDEVNAME_SIZE];
2617         struct block_device *bdev;
2618
2619         if (pd->pkt_dev == dev) {
2620                 pkt_err(pd, "recursive setup not allowed\n");
2621                 return -EBUSY;
2622         }
2623         for (i = 0; i < MAX_WRITERS; i++) {
2624                 struct pktcdvd_device *pd2 = pkt_devs[i];
2625                 if (!pd2)
2626                         continue;
2627                 if (pd2->bdev->bd_dev == dev) {
2628                         pkt_err(pd, "%s already setup\n",
2629                                 bdevname(pd2->bdev, b));
2630                         return -EBUSY;
2631                 }
2632                 if (pd2->pkt_dev == dev) {
2633                         pkt_err(pd, "can't chain pktcdvd devices\n");
2634                         return -EBUSY;
2635                 }
2636         }
2637
2638         bdev = bdget(dev);
2639         if (!bdev)
2640                 return -ENOMEM;
2641         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2642         if (ret)
2643                 return ret;
2644
2645         /* This is safe, since we have a reference from open(). */
2646         __module_get(THIS_MODULE);
2647
2648         pd->bdev = bdev;
2649         set_blocksize(bdev, CD_FRAMESIZE);
2650
2651         pkt_init_queue(pd);
2652
2653         atomic_set(&pd->cdrw.pending_bios, 0);
2654         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2655         if (IS_ERR(pd->cdrw.thread)) {
2656                 pkt_err(pd, "can't start kernel thread\n");
2657                 ret = -ENOMEM;
2658                 goto out_mem;
2659         }
2660
2661         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2662         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2663         return 0;
2664
2665 out_mem:
2666         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2667         /* This is safe: open() is still holding a reference. */
2668         module_put(THIS_MODULE);
2669         return ret;
2670 }
2671
2672 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2673 {
2674         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2675         int ret;
2676
2677         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2678                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2679
2680         mutex_lock(&pktcdvd_mutex);
2681         switch (cmd) {
2682         case CDROMEJECT:
2683                 /*
2684                  * The door gets locked when the device is opened, so we
2685                  * have to unlock it or else the eject command fails.
2686                  */
2687                 if (pd->refcnt == 1)
2688                         pkt_lock_door(pd, 0);
2689                 /* fallthru */
2690         /*
2691          * forward selected CDROM ioctls to CD-ROM, for UDF
2692          */
2693         case CDROMMULTISESSION:
2694         case CDROMREADTOCENTRY:
2695         case CDROM_LAST_WRITTEN:
2696         case CDROM_SEND_PACKET:
2697         case SCSI_IOCTL_SEND_COMMAND:
2698                 ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2699                 break;
2700
2701         default:
2702                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2703                 ret = -ENOTTY;
2704         }
2705         mutex_unlock(&pktcdvd_mutex);
2706
2707         return ret;
2708 }
2709
2710 static unsigned int pkt_check_events(struct gendisk *disk,
2711                                      unsigned int clearing)
2712 {
2713         struct pktcdvd_device *pd = disk->private_data;
2714         struct gendisk *attached_disk;
2715
2716         if (!pd)
2717                 return 0;
2718         if (!pd->bdev)
2719                 return 0;
2720         attached_disk = pd->bdev->bd_disk;
2721         if (!attached_disk || !attached_disk->fops->check_events)
2722                 return 0;
2723         return attached_disk->fops->check_events(attached_disk, clearing);
2724 }
2725
2726 static const struct block_device_operations pktcdvd_ops = {
2727         .owner =                THIS_MODULE,
2728         .open =                 pkt_open,
2729         .release =              pkt_close,
2730         .ioctl =                pkt_ioctl,
2731         .check_events =         pkt_check_events,
2732 };
2733
2734 static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2735 {
2736         return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2737 }
2738
2739 /*
2740  * Set up mapping from pktcdvd device to CD-ROM device.
2741  */
2742 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2743 {
2744         int idx;
2745         int ret = -ENOMEM;
2746         struct pktcdvd_device *pd;
2747         struct gendisk *disk;
2748
2749         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2750
2751         for (idx = 0; idx < MAX_WRITERS; idx++)
2752                 if (!pkt_devs[idx])
2753                         break;
2754         if (idx == MAX_WRITERS) {
2755                 pr_err("max %d writers supported\n", MAX_WRITERS);
2756                 ret = -EBUSY;
2757                 goto out_mutex;
2758         }
2759
2760         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2761         if (!pd)
2762                 goto out_mutex;
2763
2764         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2765                                                   sizeof(struct pkt_rb_node));
2766         if (!pd->rb_pool)
2767                 goto out_mem;
2768
2769         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2770         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2771         spin_lock_init(&pd->cdrw.active_list_lock);
2772
2773         spin_lock_init(&pd->lock);
2774         spin_lock_init(&pd->iosched.lock);
2775         bio_list_init(&pd->iosched.read_queue);
2776         bio_list_init(&pd->iosched.write_queue);
2777         sprintf(pd->name, DRIVER_NAME"%d", idx);
2778         init_waitqueue_head(&pd->wqueue);
2779         pd->bio_queue = RB_ROOT;
2780
2781         pd->write_congestion_on  = write_congestion_on;
2782         pd->write_congestion_off = write_congestion_off;
2783
2784         disk = alloc_disk(1);
2785         if (!disk)
2786                 goto out_mem;
2787         pd->disk = disk;
2788         disk->major = pktdev_major;
2789         disk->first_minor = idx;
2790         disk->fops = &pktcdvd_ops;
2791         disk->flags = GENHD_FL_REMOVABLE;
2792         strcpy(disk->disk_name, pd->name);
2793         disk->devnode = pktcdvd_devnode;
2794         disk->private_data = pd;
2795         disk->queue = blk_alloc_queue(GFP_KERNEL);
2796         if (!disk->queue)
2797                 goto out_mem2;
2798
2799         pd->pkt_dev = MKDEV(pktdev_major, idx);
2800         ret = pkt_new_dev(pd, dev);
2801         if (ret)
2802                 goto out_new_dev;
2803
2804         /* inherit events of the host device */
2805         disk->events = pd->bdev->bd_disk->events;
2806         disk->async_events = pd->bdev->bd_disk->async_events;
2807
2808         add_disk(disk);
2809
2810         pkt_sysfs_dev_new(pd);
2811         pkt_debugfs_dev_new(pd);
2812
2813         pkt_devs[idx] = pd;
2814         if (pkt_dev)
2815                 *pkt_dev = pd->pkt_dev;
2816
2817         mutex_unlock(&ctl_mutex);
2818         return 0;
2819
2820 out_new_dev:
2821         blk_cleanup_queue(disk->queue);
2822 out_mem2:
2823         put_disk(disk);
2824 out_mem:
2825         if (pd->rb_pool)
2826                 mempool_destroy(pd->rb_pool);
2827         kfree(pd);
2828 out_mutex:
2829         mutex_unlock(&ctl_mutex);
2830         pr_err("setup of pktcdvd device failed\n");
2831         return ret;
2832 }
2833
2834 /*
2835  * Tear down mapping from pktcdvd device to CD-ROM device.
2836  */
2837 static int pkt_remove_dev(dev_t pkt_dev)
2838 {
2839         struct pktcdvd_device *pd;
2840         int idx;
2841         int ret = 0;
2842
2843         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2844
2845         for (idx = 0; idx < MAX_WRITERS; idx++) {
2846                 pd = pkt_devs[idx];
2847                 if (pd && (pd->pkt_dev == pkt_dev))
2848                         break;
2849         }
2850         if (idx == MAX_WRITERS) {
2851                 pr_debug("dev not setup\n");
2852                 ret = -ENXIO;
2853                 goto out;
2854         }
2855
2856         if (pd->refcnt > 0) {
2857                 ret = -EBUSY;
2858                 goto out;
2859         }
2860         if (!IS_ERR(pd->cdrw.thread))
2861                 kthread_stop(pd->cdrw.thread);
2862
2863         pkt_devs[idx] = NULL;
2864
2865         pkt_debugfs_dev_remove(pd);
2866         pkt_sysfs_dev_remove(pd);
2867
2868         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2869
2870         remove_proc_entry(pd->name, pkt_proc);
2871         pkt_dbg(1, pd, "writer unmapped\n");
2872
2873         del_gendisk(pd->disk);
2874         blk_cleanup_queue(pd->disk->queue);
2875         put_disk(pd->disk);
2876
2877         mempool_destroy(pd->rb_pool);
2878         kfree(pd);
2879
2880         /* This is safe: open() is still holding a reference. */
2881         module_put(THIS_MODULE);
2882
2883 out:
2884         mutex_unlock(&ctl_mutex);
2885         return ret;
2886 }
2887
2888 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2889 {
2890         struct pktcdvd_device *pd;
2891
2892         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2893
2894         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2895         if (pd) {
2896                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2897                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2898         } else {
2899                 ctrl_cmd->dev = 0;
2900                 ctrl_cmd->pkt_dev = 0;
2901         }
2902         ctrl_cmd->num_devices = MAX_WRITERS;
2903
2904         mutex_unlock(&ctl_mutex);
2905 }
2906
2907 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2908 {
2909         void __user *argp = (void __user *)arg;
2910         struct pkt_ctrl_command ctrl_cmd;
2911         int ret = 0;
2912         dev_t pkt_dev = 0;
2913
2914         if (cmd != PACKET_CTRL_CMD)
2915                 return -ENOTTY;
2916
2917         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2918                 return -EFAULT;
2919
2920         switch (ctrl_cmd.command) {
2921         case PKT_CTRL_CMD_SETUP:
2922                 if (!capable(CAP_SYS_ADMIN))
2923                         return -EPERM;
2924                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2925                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2926                 break;
2927         case PKT_CTRL_CMD_TEARDOWN:
2928                 if (!capable(CAP_SYS_ADMIN))
2929                         return -EPERM;
2930                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2931                 break;
2932         case PKT_CTRL_CMD_STATUS:
2933                 pkt_get_status(&ctrl_cmd);
2934                 break;
2935         default:
2936                 return -ENOTTY;
2937         }
2938
2939         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2940                 return -EFAULT;
2941         return ret;
2942 }
2943
2944 #ifdef CONFIG_COMPAT
2945 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2946 {
2947         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2948 }
2949 #endif
2950
2951 static const struct file_operations pkt_ctl_fops = {
2952         .open           = nonseekable_open,
2953         .unlocked_ioctl = pkt_ctl_ioctl,
2954 #ifdef CONFIG_COMPAT
2955         .compat_ioctl   = pkt_ctl_compat_ioctl,
2956 #endif
2957         .owner          = THIS_MODULE,
2958         .llseek         = no_llseek,
2959 };
2960
2961 static struct miscdevice pkt_misc = {
2962         .minor          = MISC_DYNAMIC_MINOR,
2963         .name           = DRIVER_NAME,
2964         .nodename       = "pktcdvd/control",
2965         .fops           = &pkt_ctl_fops
2966 };
2967
2968 static int __init pkt_init(void)
2969 {
2970         int ret;
2971
2972         mutex_init(&ctl_mutex);
2973
2974         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2975                                         sizeof(struct packet_stacked_data));
2976         if (!psd_pool)
2977                 return -ENOMEM;
2978
2979         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2980         if (ret < 0) {
2981                 pr_err("unable to register block device\n");
2982                 goto out2;
2983         }
2984         if (!pktdev_major)
2985                 pktdev_major = ret;
2986
2987         ret = pkt_sysfs_init();
2988         if (ret)
2989                 goto out;
2990
2991         pkt_debugfs_init();
2992
2993         ret = misc_register(&pkt_misc);
2994         if (ret) {
2995                 pr_err("unable to register misc device\n");
2996                 goto out_misc;
2997         }
2998
2999         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
3000
3001         return 0;
3002
3003 out_misc:
3004         pkt_debugfs_cleanup();
3005         pkt_sysfs_cleanup();
3006 out:
3007         unregister_blkdev(pktdev_major, DRIVER_NAME);
3008 out2:
3009         mempool_destroy(psd_pool);
3010         return ret;
3011 }
3012
3013 static void __exit pkt_exit(void)
3014 {
3015         remove_proc_entry("driver/"DRIVER_NAME, NULL);
3016         misc_deregister(&pkt_misc);
3017
3018         pkt_debugfs_cleanup();
3019         pkt_sysfs_cleanup();
3020
3021         unregister_blkdev(pktdev_major, DRIVER_NAME);
3022         mempool_destroy(psd_pool);
3023 }
3024
3025 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3026 MODULE_AUTHOR("Jens Axboe <[email protected]>");
3027 MODULE_LICENSE("GPL");
3028
3029 module_init(pkt_init);
3030 module_exit(pkt_exit);