drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
  10  * DVD-RAM devices.
  11  *
  12  * Theory of operation:
  13  *
  14  * At the lowest level, there is the standard driver for the CD/DVD device,
  15  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
  16  * but it doesn't know anything about the special restrictions that apply to
  17  * packet writing. One restriction is that write requests must be aligned to
  18  * packet boundaries on the physical media, and the size of a write request
  19  * must be equal to the packet size. Another restriction is that a
  20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  21  * command, if the previous command was a write.
  22  *
  23  * The purpose of the packet writing driver is to hide these restrictions from
  24  * higher layers, such as file systems, and present a block device that can be
  25  * randomly read and written using 2kB-sized blocks.
  26  *
  27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  28  * Its data is defined by the struct packet_iosched and includes two bio
  29  * queues with pending read and write requests. These queues are processed
  30  * by the pkt_iosched_process_queue() function. The write requests in this
  31  * queue are already properly aligned and sized. This layer is responsible for
  32  * issuing the flush cache commands and scheduling the I/O in a good order.
  33  *
  34  * The next layer transforms unaligned write requests to aligned writes. This
  35  * transformation requires reading missing pieces of data from the underlying
  36  * block device, assembling the pieces to full packets and queuing them to the
  37  * packet I/O scheduler.
  38  *
  39  * At the top layer there is a custom make_request_fn function that forwards
  40  * read requests directly to the iosched queue and puts write requests in the
  41  * unaligned write queue. A kernel thread performs the necessary read
  42  * gathering to convert the unaligned writes to aligned writes and then feeds
  43  * them to the packet I/O scheduler.
  44  *
  45  *************************************************************************/
  46
  47 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  48
  49 #include <linux/pktcdvd.h>
  50 #include <linux/module.h>
  51 #include <linux/types.h>
  52 #include <linux/kernel.h>
  53 #include <linux/compat.h>
  54 #include <linux/kthread.h>
  55 #include <linux/errno.h>
  56 #include <linux/spinlock.h>
  57 #include <linux/file.h>
  58 #include <linux/proc_fs.h>
  59 #include <linux/seq_file.h>
  60 #include <linux/miscdevice.h>
  61 #include <linux/freezer.h>
  62 #include <linux/mutex.h>
  63 #include <linux/slab.h>
  64 #include <linux/backing-dev.h>
  65 #include <scsi/scsi_cmnd.h>
  66 #include <scsi/scsi_ioctl.h>
  67 #include <scsi/scsi.h>
  68 #include <linux/debugfs.h>
  69 #include <linux/device.h>
  70
  71 #include <linux/uaccess.h>
  72
  73 #define DRIVER_NAME     "pktcdvd"
  74
  75 #define pkt_err(pd, fmt, ...)                                           \
  76         pr_err("%s: " fmt, pd->name, ##__VA_ARGS__)
  77 #define pkt_notice(pd, fmt, ...)                                        \
  78         pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__)
  79 #define pkt_info(pd, fmt, ...)                                          \
  80         pr_info("%s: " fmt, pd->name, ##__VA_ARGS__)
  81
  82 #define pkt_dbg(level, pd, fmt, ...)                                    \
  83 do {                                                                    \
  84         if (level == 2 && PACKET_DEBUG >= 2)                            \
  85                 pr_notice("%s: %s():" fmt,                              \
  86                           pd->name, __func__, ##__VA_ARGS__);           \
  87         else if (level == 1 && PACKET_DEBUG >= 1)                       \
  88                 pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__);         \
  89 } while (0)
  90
  91 #define MAX_SPEED 0xffff
  92
  93 static DEFINE_MUTEX(pktcdvd_mutex);
  94 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  95 static struct proc_dir_entry *pkt_proc;
  96 static int pktdev_major;
  97 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
  98 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
  99 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
 100 static mempool_t *psd_pool;
 101 static struct bio_set *pkt_bio_set;
 102
 103 static struct class     *class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
 104 static struct dentry    *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
 105
 106 /* forward declaration */
 107 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
 108 static int pkt_remove_dev(dev_t pkt_dev);
 109 static int pkt_seq_show(struct seq_file *m, void *p);
 110
 111 static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
 112 {
 113         return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
 114 }
 115
 116 /*
 117  * create and register a pktcdvd kernel object.
 118  */
 119 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
 120                                         const char* name,
 121                                         struct kobject* parent,
 122                                         struct kobj_type* ktype)
 123 {
 124         struct pktcdvd_kobj *p;
 125         int error;
 126
 127         p = kzalloc(sizeof(*p), GFP_KERNEL);
 128         if (!p)
 129                 return NULL;
 130         p->pd = pd;
 131         error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
 132         if (error) {
 133                 kobject_put(&p->kobj);
 134                 return NULL;
 135         }
 136         kobject_uevent(&p->kobj, KOBJ_ADD);
 137         return p;
 138 }
 139 /*
 140  * remove a pktcdvd kernel object.
 141  */
 142 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 143 {
 144         if (p)
 145                 kobject_put(&p->kobj);
 146 }
 147 /*
 148  * default release function for pktcdvd kernel objects.
 149  */
 150 static void pkt_kobj_release(struct kobject *kobj)
 151 {
 152         kfree(to_pktcdvdkobj(kobj));
 153 }
 154
 155
 156 /**********************************************************
 157  *
 158  * sysfs interface for pktcdvd
 159  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 160  *
 161  **********************************************************/
 162
 163 #define DEF_ATTR(_obj,_name,_mode) \
 164         static struct attribute _obj = { .name = _name, .mode = _mode }
 165
 166 /**********************************************************
 167   /sys/class/pktcdvd/pktcdvd[0-7]/
 168                      stat/reset
 169                      stat/packets_started
 170                      stat/packets_finished
 171                      stat/kb_written
 172                      stat/kb_read
 173                      stat/kb_read_gather
 174                      write_queue/size
 175                      write_queue/congestion_off
 176                      write_queue/congestion_on
 177  **********************************************************/
 178
 179 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 180 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 181 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 182 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 183 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 184 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 185
 186 static struct attribute *kobj_pkt_attrs_stat[] = {
 187         &kobj_pkt_attr_st1,
 188         &kobj_pkt_attr_st2,
 189         &kobj_pkt_attr_st3,
 190         &kobj_pkt_attr_st4,
 191         &kobj_pkt_attr_st5,
 192         &kobj_pkt_attr_st6,
 193         NULL
 194 };
 195
 196 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 197 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 198 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 199
 200 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 201         &kobj_pkt_attr_wq1,
 202         &kobj_pkt_attr_wq2,
 203         &kobj_pkt_attr_wq3,
 204         NULL
 205 };
 206
 207 static ssize_t kobj_pkt_show(struct kobject *kobj,
 208                         struct attribute *attr, char *data)
 209 {
 210         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 211         int n = 0;
 212         int v;
 213         if (strcmp(attr->name, "packets_started") == 0) {
 214                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 215
 216         } else if (strcmp(attr->name, "packets_finished") == 0) {
 217                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 218
 219         } else if (strcmp(attr->name, "kb_written") == 0) {
 220                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 221
 222         } else if (strcmp(attr->name, "kb_read") == 0) {
 223                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 224
 225         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 226                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 227
 228         } else if (strcmp(attr->name, "size") == 0) {
 229                 spin_lock(&pd->lock);
 230                 v = pd->bio_queue_size;
 231                 spin_unlock(&pd->lock);
 232                 n = sprintf(data, "%d\n", v);
 233
 234         } else if (strcmp(attr->name, "congestion_off") == 0) {
 235                 spin_lock(&pd->lock);
 236                 v = pd->write_congestion_off;
 237                 spin_unlock(&pd->lock);
 238                 n = sprintf(data, "%d\n", v);
 239
 240         } else if (strcmp(attr->name, "congestion_on") == 0) {
 241                 spin_lock(&pd->lock);
 242                 v = pd->write_congestion_on;
 243                 spin_unlock(&pd->lock);
 244                 n = sprintf(data, "%d\n", v);
 245         }
 246         return n;
 247 }
 248
 249 static void init_write_congestion_marks(int* lo, int* hi)
 250 {
 251         if (*hi > 0) {
 252                 *hi = max(*hi, 500);
 253                 *hi = min(*hi, 1000000);
 254                 if (*lo <= 0)
 255                         *lo = *hi - 100;
 256                 else {
 257                         *lo = min(*lo, *hi - 100);
 258                         *lo = max(*lo, 100);
 259                 }
 260         } else {
 261                 *hi = -1;
 262                 *lo = -1;
 263         }
 264 }
 265
 266 static ssize_t kobj_pkt_store(struct kobject *kobj,
 267                         struct attribute *attr,
 268                         const char *data, size_t len)
 269 {
 270         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 271         int val;
 272
 273         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 274                 pd->stats.pkt_started = 0;
 275                 pd->stats.pkt_ended = 0;
 276                 pd->stats.secs_w = 0;
 277                 pd->stats.secs_rg = 0;
 278                 pd->stats.secs_r = 0;
 279
 280         } else if (strcmp(attr->name, "congestion_off") == 0
 281                    && sscanf(data, "%d", &val) == 1) {
 282                 spin_lock(&pd->lock);
 283                 pd->write_congestion_off = val;
 284                 init_write_congestion_marks(&pd->write_congestion_off,
 285                                         &pd->write_congestion_on);
 286                 spin_unlock(&pd->lock);
 287
 288         } else if (strcmp(attr->name, "congestion_on") == 0
 289                    && sscanf(data, "%d", &val) == 1) {
 290                 spin_lock(&pd->lock);
 291                 pd->write_congestion_on = val;
 292                 init_write_congestion_marks(&pd->write_congestion_off,
 293                                         &pd->write_congestion_on);
 294                 spin_unlock(&pd->lock);
 295         }
 296         return len;
 297 }
 298
 299 static const struct sysfs_ops kobj_pkt_ops = {
 300         .show = kobj_pkt_show,
 301         .store = kobj_pkt_store
 302 };
 303 static struct kobj_type kobj_pkt_type_stat = {
 304         .release = pkt_kobj_release,
 305         .sysfs_ops = &kobj_pkt_ops,
 306         .default_attrs = kobj_pkt_attrs_stat
 307 };
 308 static struct kobj_type kobj_pkt_type_wqueue = {
 309         .release = pkt_kobj_release,
 310         .sysfs_ops = &kobj_pkt_ops,
 311         .default_attrs = kobj_pkt_attrs_wqueue
 312 };
 313
 314 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 315 {
 316         if (class_pktcdvd) {
 317                 pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
 318                                         "%s", pd->name);
 319                 if (IS_ERR(pd->dev))
 320                         pd->dev = NULL;
 321         }
 322         if (pd->dev) {
 323                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 324                                         &pd->dev->kobj,
 325                                         &kobj_pkt_type_stat);
 326                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 327                                         &pd->dev->kobj,
 328                                         &kobj_pkt_type_wqueue);
 329         }
 330 }
 331
 332 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 333 {
 334         pkt_kobj_remove(pd->kobj_stat);
 335         pkt_kobj_remove(pd->kobj_wqueue);
 336         if (class_pktcdvd)
 337                 device_unregister(pd->dev);
 338 }
 339
 340
 341 /********************************************************************
 342   /sys/class/pktcdvd/
 343                      add            map block device
 344                      remove         unmap packet dev
 345                      device_map     show mappings
 346  *******************************************************************/
 347
 348 static void class_pktcdvd_release(struct class *cls)
 349 {
 350         kfree(cls);
 351 }
 352
 353 static ssize_t device_map_show(struct class *c, struct class_attribute *attr,
 354                                char *data)
 355 {
 356         int n = 0;
 357         int idx;
 358         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 359         for (idx = 0; idx < MAX_WRITERS; idx++) {
 360                 struct pktcdvd_device *pd = pkt_devs[idx];
 361                 if (!pd)
 362                         continue;
 363                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 364                         pd->name,
 365                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 366                         MAJOR(pd->bdev->bd_dev),
 367                         MINOR(pd->bdev->bd_dev));
 368         }
 369         mutex_unlock(&ctl_mutex);
 370         return n;
 371 }
 372 static CLASS_ATTR_RO(device_map);
 373
 374 static ssize_t add_store(struct class *c, struct class_attribute *attr,
 375                          const char *buf, size_t count)
 376 {
 377         unsigned int major, minor;
 378
 379         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 380                 /* pkt_setup_dev() expects caller to hold reference to self */
 381                 if (!try_module_get(THIS_MODULE))
 382                         return -ENODEV;
 383
 384                 pkt_setup_dev(MKDEV(major, minor), NULL);
 385
 386                 module_put(THIS_MODULE);
 387
 388                 return count;
 389         }
 390
 391         return -EINVAL;
 392 }
 393 static CLASS_ATTR_WO(add);
 394
 395 static ssize_t remove_store(struct class *c, struct class_attribute *attr,
 396                             const char *buf, size_t count)
 397 {
 398         unsigned int major, minor;
 399         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 400                 pkt_remove_dev(MKDEV(major, minor));
 401                 return count;
 402         }
 403         return -EINVAL;
 404 }
 405 static CLASS_ATTR_WO(remove);
 406
 407 static struct attribute *class_pktcdvd_attrs[] = {
 408         &class_attr_add.attr,
 409         &class_attr_remove.attr,
 410         &class_attr_device_map.attr,
 411         NULL,
 412 };
 413 ATTRIBUTE_GROUPS(class_pktcdvd);
 414
 415 static int pkt_sysfs_init(void)
 416 {
 417         int ret = 0;
 418
 419         /*
 420          * create control files in sysfs
 421          * /sys/class/pktcdvd/...
 422          */
 423         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 424         if (!class_pktcdvd)
 425                 return -ENOMEM;
 426         class_pktcdvd->name = DRIVER_NAME;
 427         class_pktcdvd->owner = THIS_MODULE;
 428         class_pktcdvd->class_release = class_pktcdvd_release;
 429         class_pktcdvd->class_groups = class_pktcdvd_groups;
 430         ret = class_register(class_pktcdvd);
 431         if (ret) {
 432                 kfree(class_pktcdvd);
 433                 class_pktcdvd = NULL;
 434                 pr_err("failed to create class pktcdvd\n");
 435                 return ret;
 436         }
 437         return 0;
 438 }
 439
 440 static void pkt_sysfs_cleanup(void)
 441 {
 442         if (class_pktcdvd)
 443                 class_destroy(class_pktcdvd);
 444         class_pktcdvd = NULL;
 445 }
 446
 447 /********************************************************************
 448   entries in debugfs
 449
 450   /sys/kernel/debug/pktcdvd[0-7]/
 451                         info
 452
 453  *******************************************************************/
 454
 455 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 456 {
 457         return pkt_seq_show(m, p);
 458 }
 459
 460 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 461 {
 462         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 463 }
 464
 465 static const struct file_operations debug_fops = {
 466         .open           = pkt_debugfs_fops_open,
 467         .read           = seq_read,
 468         .llseek         = seq_lseek,
 469         .release        = single_release,
 470         .owner          = THIS_MODULE,
 471 };
 472
 473 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 474 {
 475         if (!pkt_debugfs_root)
 476                 return;
 477         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 478         if (!pd->dfs_d_root)
 479                 return;
 480
 481         pd->dfs_f_info = debugfs_create_file("info", 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                              REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM);
 708         if (IS_ERR(rq))
 709                 return PTR_ERR(rq);
 710
 711         if (cgc->buflen) {
 712                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 713                                       __GFP_RECLAIM);
 714                 if (ret)
 715                         goto out;
 716         }
 717
 718         scsi_req(rq)->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 719         memcpy(scsi_req(rq)->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 720
 721         rq->timeout = 60*HZ;
 722         if (cgc->quiet)
 723                 rq->rq_flags |= RQF_QUIET;
 724
 725         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 726         if (scsi_req(rq)->result)
 727                 ret = -EIO;
 728 out:
 729         blk_put_request(rq);
 730         return ret;
 731 }
 732
 733 static const char *sense_key_string(__u8 index)
 734 {
 735         static const char * const info[] = {
 736                 "No sense", "Recovered error", "Not ready",
 737                 "Medium error", "Hardware error", "Illegal request",
 738                 "Unit attention", "Data protect", "Blank check",
 739         };
 740
 741         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 742 }
 743
 744 /*
 745  * A generic sense dump / resolve mechanism should be implemented across
 746  * all ATAPI + SCSI devices.
 747  */
 748 static void pkt_dump_sense(struct pktcdvd_device *pd,
 749                            struct packet_command *cgc)
 750 {
 751         struct request_sense *sense = cgc->sense;
 752
 753         if (sense)
 754                 pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
 755                         CDROM_PACKET_SIZE, cgc->cmd,
 756                         sense->sense_key, sense->asc, sense->ascq,
 757                         sense_key_string(sense->sense_key));
 758         else
 759                 pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 760 }
 761
 762 /*
 763  * flush the drive cache to media
 764  */
 765 static int pkt_flush_cache(struct pktcdvd_device *pd)
 766 {
 767         struct packet_command cgc;
 768
 769         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 770         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 771         cgc.quiet = 1;
 772
 773         /*
 774          * the IMMED bit -- we default to not setting it, although that
 775          * would allow a much faster close, this is safer
 776          */
 777 #if 0
 778         cgc.cmd[1] = 1 << 1;
 779 #endif
 780         return pkt_generic_packet(pd, &cgc);
 781 }
 782
 783 /*
 784  * speed is given as the normal factor, e.g. 4 for 4x
 785  */
 786 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 787                                 unsigned write_speed, unsigned read_speed)
 788 {
 789         struct packet_command cgc;
 790         struct request_sense sense;
 791         int ret;
 792
 793         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 794         cgc.sense = &sense;
 795         cgc.cmd[0] = GPCMD_SET_SPEED;
 796         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 797         cgc.cmd[3] = read_speed & 0xff;
 798         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 799         cgc.cmd[5] = write_speed & 0xff;
 800
 801         if ((ret = pkt_generic_packet(pd, &cgc)))
 802                 pkt_dump_sense(pd, &cgc);
 803
 804         return ret;
 805 }
 806
 807 /*
 808  * Queue a bio for processing by the low-level CD device. Must be called
 809  * from process context.
 810  */
 811 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 812 {
 813         spin_lock(&pd->iosched.lock);
 814         if (bio_data_dir(bio) == READ)
 815                 bio_list_add(&pd->iosched.read_queue, bio);
 816         else
 817                 bio_list_add(&pd->iosched.write_queue, bio);
 818         spin_unlock(&pd->iosched.lock);
 819
 820         atomic_set(&pd->iosched.attention, 1);
 821         wake_up(&pd->wqueue);
 822 }
 823
 824 /*
 825  * Process the queued read/write requests. This function handles special
 826  * requirements for CDRW drives:
 827  * - A cache flush command must be inserted before a read request if the
 828  *   previous request was a write.
 829  * - Switching between reading and writing is slow, so don't do it more often
 830  *   than necessary.
 831  * - Optimize for throughput at the expense of latency. This means that streaming
 832  *   writes will never be interrupted by a read, but if the drive has to seek
 833  *   before the next write, switch to reading instead if there are any pending
 834  *   read requests.
 835  * - Set the read speed according to current usage pattern. When only reading
 836  *   from the device, it's best to use the highest possible read speed, but
 837  *   when switching often between reading and writing, it's better to have the
 838  *   same read and write speeds.
 839  */
 840 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 841 {
 842
 843         if (atomic_read(&pd->iosched.attention) == 0)
 844                 return;
 845         atomic_set(&pd->iosched.attention, 0);
 846
 847         for (;;) {
 848                 struct bio *bio;
 849                 int reads_queued, writes_queued;
 850
 851                 spin_lock(&pd->iosched.lock);
 852                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 853                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 854                 spin_unlock(&pd->iosched.lock);
 855
 856                 if (!reads_queued && !writes_queued)
 857                         break;
 858
 859                 if (pd->iosched.writing) {
 860                         int need_write_seek = 1;
 861                         spin_lock(&pd->iosched.lock);
 862                         bio = bio_list_peek(&pd->iosched.write_queue);
 863                         spin_unlock(&pd->iosched.lock);
 864                         if (bio && (bio->bi_iter.bi_sector ==
 865                                     pd->iosched.last_write))
 866                                 need_write_seek = 0;
 867                         if (need_write_seek && reads_queued) {
 868                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 869                                         pkt_dbg(2, pd, "write, waiting\n");
 870                                         break;
 871                                 }
 872                                 pkt_flush_cache(pd);
 873                                 pd->iosched.writing = 0;
 874                         }
 875                 } else {
 876                         if (!reads_queued && writes_queued) {
 877                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 878                                         pkt_dbg(2, pd, "read, waiting\n");
 879                                         break;
 880                                 }
 881                                 pd->iosched.writing = 1;
 882                         }
 883                 }
 884
 885                 spin_lock(&pd->iosched.lock);
 886                 if (pd->iosched.writing)
 887                         bio = bio_list_pop(&pd->iosched.write_queue);
 888                 else
 889                         bio = bio_list_pop(&pd->iosched.read_queue);
 890                 spin_unlock(&pd->iosched.lock);
 891
 892                 if (!bio)
 893                         continue;
 894
 895                 if (bio_data_dir(bio) == READ)
 896                         pd->iosched.successive_reads +=
 897                                 bio->bi_iter.bi_size >> 10;
 898                 else {
 899                         pd->iosched.successive_reads = 0;
 900                         pd->iosched.last_write = bio_end_sector(bio);
 901                 }
 902                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 903                         if (pd->read_speed == pd->write_speed) {
 904                                 pd->read_speed = MAX_SPEED;
 905                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 906                         }
 907                 } else {
 908                         if (pd->read_speed != pd->write_speed) {
 909                                 pd->read_speed = pd->write_speed;
 910                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 911                         }
 912                 }
 913
 914                 atomic_inc(&pd->cdrw.pending_bios);
 915                 generic_make_request(bio);
 916         }
 917 }
 918
 919 /*
 920  * Special care is needed if the underlying block device has a small
 921  * max_phys_segments value.
 922  */
 923 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 924 {
 925         if ((pd->settings.size << 9) / CD_FRAMESIZE
 926             <= queue_max_segments(q)) {
 927                 /*
 928                  * The cdrom device can handle one segment/frame
 929                  */
 930                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 931                 return 0;
 932         } else if ((pd->settings.size << 9) / PAGE_SIZE
 933                    <= queue_max_segments(q)) {
 934                 /*
 935                  * We can handle this case at the expense of some extra memory
 936                  * copies during write operations
 937                  */
 938                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 939                 return 0;
 940         } else {
 941                 pkt_err(pd, "cdrom max_phys_segments too small\n");
 942                 return -EIO;
 943         }
 944 }
 945
 946 static void pkt_end_io_read(struct bio *bio)
 947 {
 948         struct packet_data *pkt = bio->bi_private;
 949         struct pktcdvd_device *pd = pkt->pd;
 950         BUG_ON(!pd);
 951
 952         pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
 953                 bio, (unsigned long long)pkt->sector,
 954                 (unsigned long long)bio->bi_iter.bi_sector, bio->bi_status);
 955
 956         if (bio->bi_status)
 957                 atomic_inc(&pkt->io_errors);
 958         if (atomic_dec_and_test(&pkt->io_wait)) {
 959                 atomic_inc(&pkt->run_sm);
 960                 wake_up(&pd->wqueue);
 961         }
 962         pkt_bio_finished(pd);
 963 }
 964
 965 static void pkt_end_io_packet_write(struct bio *bio)
 966 {
 967         struct packet_data *pkt = bio->bi_private;
 968         struct pktcdvd_device *pd = pkt->pd;
 969         BUG_ON(!pd);
 970
 971         pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_status);
 972
 973         pd->stats.pkt_ended++;
 974
 975         pkt_bio_finished(pd);
 976         atomic_dec(&pkt->io_wait);
 977         atomic_inc(&pkt->run_sm);
 978         wake_up(&pd->wqueue);
 979 }
 980
 981 /*
 982  * Schedule reads for the holes in a packet
 983  */
 984 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 985 {
 986         int frames_read = 0;
 987         struct bio *bio;
 988         int f;
 989         char written[PACKET_MAX_SIZE];
 990
 991         BUG_ON(bio_list_empty(&pkt->orig_bios));
 992
 993         atomic_set(&pkt->io_wait, 0);
 994         atomic_set(&pkt->io_errors, 0);
 995
 996         /*
 997          * Figure out which frames we need to read before we can write.
 998          */
 999         memset(written, 0, sizeof(written));
1000         spin_lock(&pkt->lock);
1001         bio_list_for_each(bio, &pkt->orig_bios) {
1002                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1003                         (CD_FRAMESIZE >> 9);
1004                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1005                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1006                 BUG_ON(first_frame < 0);
1007                 BUG_ON(first_frame + num_frames > pkt->frames);
1008                 for (f = first_frame; f < first_frame + num_frames; f++)
1009                         written[f] = 1;
1010         }
1011         spin_unlock(&pkt->lock);
1012
1013         if (pkt->cache_valid) {
1014                 pkt_dbg(2, pd, "zone %llx cached\n",
1015                         (unsigned long long)pkt->sector);
1016                 goto out_account;
1017         }
1018
1019         /*
1020          * Schedule reads for missing parts of the packet.
1021          */
1022         for (f = 0; f < pkt->frames; f++) {
1023                 int p, offset;
1024
1025                 if (written[f])
1026                         continue;
1027
1028                 bio = pkt->r_bios[f];
1029                 bio_reset(bio);
1030                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1031                 bio_set_dev(bio, pd->bdev);
1032                 bio->bi_end_io = pkt_end_io_read;
1033                 bio->bi_private = pkt;
1034
1035                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1036                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1037                 pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1038                         f, pkt->pages[p], offset);
1039                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1040                         BUG();
1041
1042                 atomic_inc(&pkt->io_wait);
1043                 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1044                 pkt_queue_bio(pd, bio);
1045                 frames_read++;
1046         }
1047
1048 out_account:
1049         pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1050                 frames_read, (unsigned long long)pkt->sector);
1051         pd->stats.pkt_started++;
1052         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1053 }
1054
1055 /*
1056  * Find a packet matching zone, or the least recently used packet if
1057  * there is no match.
1058  */
1059 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1060 {
1061         struct packet_data *pkt;
1062
1063         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1064                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1065                         list_del_init(&pkt->list);
1066                         if (pkt->sector != zone)
1067                                 pkt->cache_valid = 0;
1068                         return pkt;
1069                 }
1070         }
1071         BUG();
1072         return NULL;
1073 }
1074
1075 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1076 {
1077         if (pkt->cache_valid) {
1078                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1079         } else {
1080                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1081         }
1082 }
1083
1084 /*
1085  * recover a failed write, query for relocation if possible
1086  *
1087  * returns 1 if recovery is possible, or 0 if not
1088  *
1089  */
1090 static int pkt_start_recovery(struct packet_data *pkt)
1091 {
1092         /*
1093          * FIXME. We need help from the file system to implement
1094          * recovery handling.
1095          */
1096         return 0;
1097 #if 0
1098         struct request *rq = pkt->rq;
1099         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1100         struct block_device *pkt_bdev;
1101         struct super_block *sb = NULL;
1102         unsigned long old_block, new_block;
1103         sector_t new_sector;
1104
1105         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1106         if (pkt_bdev) {
1107                 sb = get_super(pkt_bdev);
1108                 bdput(pkt_bdev);
1109         }
1110
1111         if (!sb)
1112                 return 0;
1113
1114         if (!sb->s_op->relocate_blocks)
1115                 goto out;
1116
1117         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1118         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1119                 goto out;
1120
1121         new_sector = new_block * (CD_FRAMESIZE >> 9);
1122         pkt->sector = new_sector;
1123
1124         bio_reset(pkt->bio);
1125         bio_set_set(pkt->bio, pd->bdev);
1126         bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0);
1127         pkt->bio->bi_iter.bi_sector = new_sector;
1128         pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1129         pkt->bio->bi_vcnt = pkt->frames;
1130
1131         pkt->bio->bi_end_io = pkt_end_io_packet_write;
1132         pkt->bio->bi_private = pkt;
1133
1134         drop_super(sb);
1135         return 1;
1136
1137 out:
1138         drop_super(sb);
1139         return 0;
1140 #endif
1141 }
1142
1143 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1144 {
1145 #if PACKET_DEBUG > 1
1146         static const char *state_name[] = {
1147                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1148         };
1149         enum packet_data_state old_state = pkt->state;
1150         pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1151                 pkt->id, (unsigned long long)pkt->sector,
1152                 state_name[old_state], state_name[state]);
1153 #endif
1154         pkt->state = state;
1155 }
1156
1157 /*
1158  * Scan the work queue to see if we can start a new packet.
1159  * returns non-zero if any work was done.
1160  */
1161 static int pkt_handle_queue(struct pktcdvd_device *pd)
1162 {
1163         struct packet_data *pkt, *p;
1164         struct bio *bio = NULL;
1165         sector_t zone = 0; /* Suppress gcc warning */
1166         struct pkt_rb_node *node, *first_node;
1167         struct rb_node *n;
1168         int wakeup;
1169
1170         atomic_set(&pd->scan_queue, 0);
1171
1172         if (list_empty(&pd->cdrw.pkt_free_list)) {
1173                 pkt_dbg(2, pd, "no pkt\n");
1174                 return 0;
1175         }
1176
1177         /*
1178          * Try to find a zone we are not already working on.
1179          */
1180         spin_lock(&pd->lock);
1181         first_node = pkt_rbtree_find(pd, pd->current_sector);
1182         if (!first_node) {
1183                 n = rb_first(&pd->bio_queue);
1184                 if (n)
1185                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1186         }
1187         node = first_node;
1188         while (node) {
1189                 bio = node->bio;
1190                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1191                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1192                         if (p->sector == zone) {
1193                                 bio = NULL;
1194                                 goto try_next_bio;
1195                         }
1196                 }
1197                 break;
1198 try_next_bio:
1199                 node = pkt_rbtree_next(node);
1200                 if (!node) {
1201                         n = rb_first(&pd->bio_queue);
1202                         if (n)
1203                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1204                 }
1205                 if (node == first_node)
1206                         node = NULL;
1207         }
1208         spin_unlock(&pd->lock);
1209         if (!bio) {
1210                 pkt_dbg(2, pd, "no bio\n");
1211                 return 0;
1212         }
1213
1214         pkt = pkt_get_packet_data(pd, zone);
1215
1216         pd->current_sector = zone + pd->settings.size;
1217         pkt->sector = zone;
1218         BUG_ON(pkt->frames != pd->settings.size >> 2);
1219         pkt->write_size = 0;
1220
1221         /*
1222          * Scan work queue for bios in the same zone and link them
1223          * to this packet.
1224          */
1225         spin_lock(&pd->lock);
1226         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1227         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1228                 bio = node->bio;
1229                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1230                         get_zone(bio->bi_iter.bi_sector, pd));
1231                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1232                         break;
1233                 pkt_rbtree_erase(pd, node);
1234                 spin_lock(&pkt->lock);
1235                 bio_list_add(&pkt->orig_bios, bio);
1236                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1237                 spin_unlock(&pkt->lock);
1238         }
1239         /* check write congestion marks, and if bio_queue_size is
1240            below, wake up any waiters */
1241         wakeup = (pd->write_congestion_on > 0
1242                         && pd->bio_queue_size <= pd->write_congestion_off);
1243         spin_unlock(&pd->lock);
1244         if (wakeup) {
1245                 clear_bdi_congested(pd->disk->queue->backing_dev_info,
1246                                         BLK_RW_ASYNC);
1247         }
1248
1249         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1250         pkt_set_state(pkt, PACKET_WAITING_STATE);
1251         atomic_set(&pkt->run_sm, 1);
1252
1253         spin_lock(&pd->cdrw.active_list_lock);
1254         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1255         spin_unlock(&pd->cdrw.active_list_lock);
1256
1257         return 1;
1258 }
1259
1260 /*
1261  * Assemble a bio to write one packet and queue the bio for processing
1262  * by the underlying block device.
1263  */
1264 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1265 {
1266         int f;
1267
1268         bio_reset(pkt->w_bio);
1269         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1270         bio_set_dev(pkt->w_bio, pd->bdev);
1271         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1272         pkt->w_bio->bi_private = pkt;
1273
1274         /* XXX: locking? */
1275         for (f = 0; f < pkt->frames; f++) {
1276                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1277                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1278
1279                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1280                         BUG();
1281         }
1282         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1283
1284         /*
1285          * Fill-in bvec with data from orig_bios.
1286          */
1287         spin_lock(&pkt->lock);
1288         bio_copy_data(pkt->w_bio, pkt->orig_bios.head);
1289
1290         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1291         spin_unlock(&pkt->lock);
1292
1293         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1294                 pkt->write_size, (unsigned long long)pkt->sector);
1295
1296         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1297                 pkt->cache_valid = 1;
1298         else
1299                 pkt->cache_valid = 0;
1300
1301         /* Start the write request */
1302         atomic_set(&pkt->io_wait, 1);
1303         bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
1304         pkt_queue_bio(pd, pkt->w_bio);
1305 }
1306
1307 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1308 {
1309         struct bio *bio;
1310
1311         if (status)
1312                 pkt->cache_valid = 0;
1313
1314         /* Finish all bios corresponding to this packet */
1315         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1316                 bio->bi_status = status;
1317                 bio_endio(bio);
1318         }
1319 }
1320
1321 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1322 {
1323         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1324
1325         for (;;) {
1326                 switch (pkt->state) {
1327                 case PACKET_WAITING_STATE:
1328                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1329                                 return;
1330
1331                         pkt->sleep_time = 0;
1332                         pkt_gather_data(pd, pkt);
1333                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1334                         break;
1335
1336                 case PACKET_READ_WAIT_STATE:
1337                         if (atomic_read(&pkt->io_wait) > 0)
1338                                 return;
1339
1340                         if (atomic_read(&pkt->io_errors) > 0) {
1341                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1342                         } else {
1343                                 pkt_start_write(pd, pkt);
1344                         }
1345                         break;
1346
1347                 case PACKET_WRITE_WAIT_STATE:
1348                         if (atomic_read(&pkt->io_wait) > 0)
1349                                 return;
1350
1351                         if (!pkt->w_bio->bi_status) {
1352                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1353                         } else {
1354                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1355                         }
1356                         break;
1357
1358                 case PACKET_RECOVERY_STATE:
1359                         if (pkt_start_recovery(pkt)) {
1360                                 pkt_start_write(pd, pkt);
1361                         } else {
1362                                 pkt_dbg(2, pd, "No recovery possible\n");
1363                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1364                         }
1365                         break;
1366
1367                 case PACKET_FINISHED_STATE:
1368                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1369                         return;
1370
1371                 default:
1372                         BUG();
1373                         break;
1374                 }
1375         }
1376 }
1377
1378 static void pkt_handle_packets(struct pktcdvd_device *pd)
1379 {
1380         struct packet_data *pkt, *next;
1381
1382         /*
1383          * Run state machine for active packets
1384          */
1385         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1386                 if (atomic_read(&pkt->run_sm) > 0) {
1387                         atomic_set(&pkt->run_sm, 0);
1388                         pkt_run_state_machine(pd, pkt);
1389                 }
1390         }
1391
1392         /*
1393          * Move no longer active packets to the free list
1394          */
1395         spin_lock(&pd->cdrw.active_list_lock);
1396         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1397                 if (pkt->state == PACKET_FINISHED_STATE) {
1398                         list_del(&pkt->list);
1399                         pkt_put_packet_data(pd, pkt);
1400                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1401                         atomic_set(&pd->scan_queue, 1);
1402                 }
1403         }
1404         spin_unlock(&pd->cdrw.active_list_lock);
1405 }
1406
1407 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1408 {
1409         struct packet_data *pkt;
1410         int i;
1411
1412         for (i = 0; i < PACKET_NUM_STATES; i++)
1413                 states[i] = 0;
1414
1415         spin_lock(&pd->cdrw.active_list_lock);
1416         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1417                 states[pkt->state]++;
1418         }
1419         spin_unlock(&pd->cdrw.active_list_lock);
1420 }
1421
1422 /*
1423  * kcdrwd is woken up when writes have been queued for one of our
1424  * registered devices
1425  */
1426 static int kcdrwd(void *foobar)
1427 {
1428         struct pktcdvd_device *pd = foobar;
1429         struct packet_data *pkt;
1430         long min_sleep_time, residue;
1431
1432         set_user_nice(current, MIN_NICE);
1433         set_freezable();
1434
1435         for (;;) {
1436                 DECLARE_WAITQUEUE(wait, current);
1437
1438                 /*
1439                  * Wait until there is something to do
1440                  */
1441                 add_wait_queue(&pd->wqueue, &wait);
1442                 for (;;) {
1443                         set_current_state(TASK_INTERRUPTIBLE);
1444
1445                         /* Check if we need to run pkt_handle_queue */
1446                         if (atomic_read(&pd->scan_queue) > 0)
1447                                 goto work_to_do;
1448
1449                         /* Check if we need to run the state machine for some packet */
1450                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1451                                 if (atomic_read(&pkt->run_sm) > 0)
1452                                         goto work_to_do;
1453                         }
1454
1455                         /* Check if we need to process the iosched queues */
1456                         if (atomic_read(&pd->iosched.attention) != 0)
1457                                 goto work_to_do;
1458
1459                         /* Otherwise, go to sleep */
1460                         if (PACKET_DEBUG > 1) {
1461                                 int states[PACKET_NUM_STATES];
1462                                 pkt_count_states(pd, states);
1463                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1464                                         states[0], states[1], states[2],
1465                                         states[3], states[4], states[5]);
1466                         }
1467
1468                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1469                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1470                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1471                                         min_sleep_time = pkt->sleep_time;
1472                         }
1473
1474                         pkt_dbg(2, pd, "sleeping\n");
1475                         residue = schedule_timeout(min_sleep_time);
1476                         pkt_dbg(2, pd, "wake up\n");
1477
1478                         /* make swsusp happy with our thread */
1479                         try_to_freeze();
1480
1481                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1482                                 if (!pkt->sleep_time)
1483                                         continue;
1484                                 pkt->sleep_time -= min_sleep_time - residue;
1485                                 if (pkt->sleep_time <= 0) {
1486                                         pkt->sleep_time = 0;
1487                                         atomic_inc(&pkt->run_sm);
1488                                 }
1489                         }
1490
1491                         if (kthread_should_stop())
1492                                 break;
1493                 }
1494 work_to_do:
1495                 set_current_state(TASK_RUNNING);
1496                 remove_wait_queue(&pd->wqueue, &wait);
1497
1498                 if (kthread_should_stop())
1499                         break;
1500
1501                 /*
1502                  * if pkt_handle_queue returns true, we can queue
1503                  * another request.
1504                  */
1505                 while (pkt_handle_queue(pd))
1506                         ;
1507
1508                 /*
1509                  * Handle packet state machine
1510                  */
1511                 pkt_handle_packets(pd);
1512
1513                 /*
1514                  * Handle iosched queues
1515                  */
1516                 pkt_iosched_process_queue(pd);
1517         }
1518
1519         return 0;
1520 }
1521
1522 static void pkt_print_settings(struct pktcdvd_device *pd)
1523 {
1524         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1525                  pd->settings.fp ? "Fixed" : "Variable",
1526                  pd->settings.size >> 2,
1527                  pd->settings.block_mode == 8 ? '1' : '2');
1528 }
1529
1530 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1531 {
1532         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1533
1534         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1535         cgc->cmd[2] = page_code | (page_control << 6);
1536         cgc->cmd[7] = cgc->buflen >> 8;
1537         cgc->cmd[8] = cgc->buflen & 0xff;
1538         cgc->data_direction = CGC_DATA_READ;
1539         return pkt_generic_packet(pd, cgc);
1540 }
1541
1542 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1543 {
1544         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1545         memset(cgc->buffer, 0, 2);
1546         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1547         cgc->cmd[1] = 0x10;             /* PF */
1548         cgc->cmd[7] = cgc->buflen >> 8;
1549         cgc->cmd[8] = cgc->buflen & 0xff;
1550         cgc->data_direction = CGC_DATA_WRITE;
1551         return pkt_generic_packet(pd, cgc);
1552 }
1553
1554 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1555 {
1556         struct packet_command cgc;
1557         int ret;
1558
1559         /* set up command and get the disc info */
1560         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1561         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1562         cgc.cmd[8] = cgc.buflen = 2;
1563         cgc.quiet = 1;
1564
1565         if ((ret = pkt_generic_packet(pd, &cgc)))
1566                 return ret;
1567
1568         /* not all drives have the same disc_info length, so requeue
1569          * packet with the length the drive tells us it can supply
1570          */
1571         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1572                      sizeof(di->disc_information_length);
1573
1574         if (cgc.buflen > sizeof(disc_information))
1575                 cgc.buflen = sizeof(disc_information);
1576
1577         cgc.cmd[8] = cgc.buflen;
1578         return pkt_generic_packet(pd, &cgc);
1579 }
1580
1581 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1582 {
1583         struct packet_command cgc;
1584         int ret;
1585
1586         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1587         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1588         cgc.cmd[1] = type & 3;
1589         cgc.cmd[4] = (track & 0xff00) >> 8;
1590         cgc.cmd[5] = track & 0xff;
1591         cgc.cmd[8] = 8;
1592         cgc.quiet = 1;
1593
1594         if ((ret = pkt_generic_packet(pd, &cgc)))
1595                 return ret;
1596
1597         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1598                      sizeof(ti->track_information_length);
1599
1600         if (cgc.buflen > sizeof(track_information))
1601                 cgc.buflen = sizeof(track_information);
1602
1603         cgc.cmd[8] = cgc.buflen;
1604         return pkt_generic_packet(pd, &cgc);
1605 }
1606
1607 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1608                                                 long *last_written)
1609 {
1610         disc_information di;
1611         track_information ti;
1612         __u32 last_track;
1613         int ret = -1;
1614
1615         if ((ret = pkt_get_disc_info(pd, &di)))
1616                 return ret;
1617
1618         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1619         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1620                 return ret;
1621
1622         /* if this track is blank, try the previous. */
1623         if (ti.blank) {
1624                 last_track--;
1625                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1626                         return ret;
1627         }
1628
1629         /* if last recorded field is valid, return it. */
1630         if (ti.lra_v) {
1631                 *last_written = be32_to_cpu(ti.last_rec_address);
1632         } else {
1633                 /* make it up instead */
1634                 *last_written = be32_to_cpu(ti.track_start) +
1635                                 be32_to_cpu(ti.track_size);
1636                 if (ti.free_blocks)
1637                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1638         }
1639         return 0;
1640 }
1641
1642 /*
1643  * write mode select package based on pd->settings
1644  */
1645 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1646 {
1647         struct packet_command cgc;
1648         struct request_sense sense;
1649         write_param_page *wp;
1650         char buffer[128];
1651         int ret, size;
1652
1653         /* doesn't apply to DVD+RW or DVD-RAM */
1654         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1655                 return 0;
1656
1657         memset(buffer, 0, sizeof(buffer));
1658         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1659         cgc.sense = &sense;
1660         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1661                 pkt_dump_sense(pd, &cgc);
1662                 return ret;
1663         }
1664
1665         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1666         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1667         if (size > sizeof(buffer))
1668                 size = sizeof(buffer);
1669
1670         /*
1671          * now get it all
1672          */
1673         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1674         cgc.sense = &sense;
1675         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1676                 pkt_dump_sense(pd, &cgc);
1677                 return ret;
1678         }
1679
1680         /*
1681          * write page is offset header + block descriptor length
1682          */
1683         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1684
1685         wp->fp = pd->settings.fp;
1686         wp->track_mode = pd->settings.track_mode;
1687         wp->write_type = pd->settings.write_type;
1688         wp->data_block_type = pd->settings.block_mode;
1689
1690         wp->multi_session = 0;
1691
1692 #ifdef PACKET_USE_LS
1693         wp->link_size = 7;
1694         wp->ls_v = 1;
1695 #endif
1696
1697         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1698                 wp->session_format = 0;
1699                 wp->subhdr2 = 0x20;
1700         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1701                 wp->session_format = 0x20;
1702                 wp->subhdr2 = 8;
1703 #if 0
1704                 wp->mcn[0] = 0x80;
1705                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1706 #endif
1707         } else {
1708                 /*
1709                  * paranoia
1710                  */
1711                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1712                 return 1;
1713         }
1714         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1715
1716         cgc.buflen = cgc.cmd[8] = size;
1717         if ((ret = pkt_mode_select(pd, &cgc))) {
1718                 pkt_dump_sense(pd, &cgc);
1719                 return ret;
1720         }
1721
1722         pkt_print_settings(pd);
1723         return 0;
1724 }
1725
1726 /*
1727  * 1 -- we can write to this track, 0 -- we can't
1728  */
1729 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1730 {
1731         switch (pd->mmc3_profile) {
1732                 case 0x1a: /* DVD+RW */
1733                 case 0x12: /* DVD-RAM */
1734                         /* The track is always writable on DVD+RW/DVD-RAM */
1735                         return 1;
1736                 default:
1737                         break;
1738         }
1739
1740         if (!ti->packet || !ti->fp)
1741                 return 0;
1742
1743         /*
1744          * "good" settings as per Mt Fuji.
1745          */
1746         if (ti->rt == 0 && ti->blank == 0)
1747                 return 1;
1748
1749         if (ti->rt == 0 && ti->blank == 1)
1750                 return 1;
1751
1752         if (ti->rt == 1 && ti->blank == 0)
1753                 return 1;
1754
1755         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1756         return 0;
1757 }
1758
1759 /*
1760  * 1 -- we can write to this disc, 0 -- we can't
1761  */
1762 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1763 {
1764         switch (pd->mmc3_profile) {
1765                 case 0x0a: /* CD-RW */
1766                 case 0xffff: /* MMC3 not supported */
1767                         break;
1768                 case 0x1a: /* DVD+RW */
1769                 case 0x13: /* DVD-RW */
1770                 case 0x12: /* DVD-RAM */
1771                         return 1;
1772                 default:
1773                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1774                                 pd->mmc3_profile);
1775                         return 0;
1776         }
1777
1778         /*
1779          * for disc type 0xff we should probably reserve a new track.
1780          * but i'm not sure, should we leave this to user apps? probably.
1781          */
1782         if (di->disc_type == 0xff) {
1783                 pkt_notice(pd, "unknown disc - no track?\n");
1784                 return 0;
1785         }
1786
1787         if (di->disc_type != 0x20 && di->disc_type != 0) {
1788                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1789                 return 0;
1790         }
1791
1792         if (di->erasable == 0) {
1793                 pkt_notice(pd, "disc not erasable\n");
1794                 return 0;
1795         }
1796
1797         if (di->border_status == PACKET_SESSION_RESERVED) {
1798                 pkt_err(pd, "can't write to last track (reserved)\n");
1799                 return 0;
1800         }
1801
1802         return 1;
1803 }
1804
1805 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1806 {
1807         struct packet_command cgc;
1808         unsigned char buf[12];
1809         disc_information di;
1810         track_information ti;
1811         int ret, track;
1812
1813         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1814         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1815         cgc.cmd[8] = 8;
1816         ret = pkt_generic_packet(pd, &cgc);
1817         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1818
1819         memset(&di, 0, sizeof(disc_information));
1820         memset(&ti, 0, sizeof(track_information));
1821
1822         if ((ret = pkt_get_disc_info(pd, &di))) {
1823                 pkt_err(pd, "failed get_disc\n");
1824                 return ret;
1825         }
1826
1827         if (!pkt_writable_disc(pd, &di))
1828                 return -EROFS;
1829
1830         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1831
1832         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1833         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1834                 pkt_err(pd, "failed get_track\n");
1835                 return ret;
1836         }
1837
1838         if (!pkt_writable_track(pd, &ti)) {
1839                 pkt_err(pd, "can't write to this track\n");
1840                 return -EROFS;
1841         }
1842
1843         /*
1844          * we keep packet size in 512 byte units, makes it easier to
1845          * deal with request calculations.
1846          */
1847         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1848         if (pd->settings.size == 0) {
1849                 pkt_notice(pd, "detected zero packet size!\n");
1850                 return -ENXIO;
1851         }
1852         if (pd->settings.size > PACKET_MAX_SECTORS) {
1853                 pkt_err(pd, "packet size is too big\n");
1854                 return -EROFS;
1855         }
1856         pd->settings.fp = ti.fp;
1857         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1858
1859         if (ti.nwa_v) {
1860                 pd->nwa = be32_to_cpu(ti.next_writable);
1861                 set_bit(PACKET_NWA_VALID, &pd->flags);
1862         }
1863
1864         /*
1865          * in theory we could use lra on -RW media as well and just zero
1866          * blocks that haven't been written yet, but in practice that
1867          * is just a no-go. we'll use that for -R, naturally.
1868          */
1869         if (ti.lra_v) {
1870                 pd->lra = be32_to_cpu(ti.last_rec_address);
1871                 set_bit(PACKET_LRA_VALID, &pd->flags);
1872         } else {
1873                 pd->lra = 0xffffffff;
1874                 set_bit(PACKET_LRA_VALID, &pd->flags);
1875         }
1876
1877         /*
1878          * fine for now
1879          */
1880         pd->settings.link_loss = 7;
1881         pd->settings.write_type = 0;    /* packet */
1882         pd->settings.track_mode = ti.track_mode;
1883
1884         /*
1885          * mode1 or mode2 disc
1886          */
1887         switch (ti.data_mode) {
1888                 case PACKET_MODE1:
1889                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1890                         break;
1891                 case PACKET_MODE2:
1892                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1893                         break;
1894                 default:
1895                         pkt_err(pd, "unknown data mode\n");
1896                         return -EROFS;
1897         }
1898         return 0;
1899 }
1900
1901 /*
1902  * enable/disable write caching on drive
1903  */
1904 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1905                                                 int set)
1906 {
1907         struct packet_command cgc;
1908         struct request_sense sense;
1909         unsigned char buf[64];
1910         int ret;
1911
1912         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1913         cgc.sense = &sense;
1914         cgc.buflen = pd->mode_offset + 12;
1915
1916         /*
1917          * caching mode page might not be there, so quiet this command
1918          */
1919         cgc.quiet = 1;
1920
1921         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1922                 return ret;
1923
1924         buf[pd->mode_offset + 10] |= (!!set << 2);
1925
1926         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1927         ret = pkt_mode_select(pd, &cgc);
1928         if (ret) {
1929                 pkt_err(pd, "write caching control failed\n");
1930                 pkt_dump_sense(pd, &cgc);
1931         } else if (!ret && set)
1932                 pkt_notice(pd, "enabled write caching\n");
1933         return ret;
1934 }
1935
1936 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1937 {
1938         struct packet_command cgc;
1939
1940         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1941         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1942         cgc.cmd[4] = lockflag ? 1 : 0;
1943         return pkt_generic_packet(pd, &cgc);
1944 }
1945
1946 /*
1947  * Returns drive maximum write speed
1948  */
1949 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1950                                                 unsigned *write_speed)
1951 {
1952         struct packet_command cgc;
1953         struct request_sense sense;
1954         unsigned char buf[256+18];
1955         unsigned char *cap_buf;
1956         int ret, offset;
1957
1958         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1959         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1960         cgc.sense = &sense;
1961
1962         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1963         if (ret) {
1964                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1965                              sizeof(struct mode_page_header);
1966                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1967                 if (ret) {
1968                         pkt_dump_sense(pd, &cgc);
1969                         return ret;
1970                 }
1971         }
1972
1973         offset = 20;                        /* Obsoleted field, used by older drives */
1974         if (cap_buf[1] >= 28)
1975                 offset = 28;                /* Current write speed selected */
1976         if (cap_buf[1] >= 30) {
1977                 /* If the drive reports at least one "Logical Unit Write
1978                  * Speed Performance Descriptor Block", use the information
1979                  * in the first block. (contains the highest speed)
1980                  */
1981                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1982                 if (num_spdb > 0)
1983                         offset = 34;
1984         }
1985
1986         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1987         return 0;
1988 }
1989
1990 /* These tables from cdrecord - I don't have orange book */
1991 /* standard speed CD-RW (1-4x) */
1992 static char clv_to_speed[16] = {
1993         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1994            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1995 };
1996 /* high speed CD-RW (-10x) */
1997 static char hs_clv_to_speed[16] = {
1998         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1999            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2000 };
2001 /* ultra high speed CD-RW */
2002 static char us_clv_to_speed[16] = {
2003         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2004            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2005 };
2006
2007 /*
2008  * reads the maximum media speed from ATIP
2009  */
2010 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2011                                                 unsigned *speed)
2012 {
2013         struct packet_command cgc;
2014         struct request_sense sense;
2015         unsigned char buf[64];
2016         unsigned int size, st, sp;
2017         int ret;
2018
2019         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2020         cgc.sense = &sense;
2021         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2022         cgc.cmd[1] = 2;
2023         cgc.cmd[2] = 4; /* READ ATIP */
2024         cgc.cmd[8] = 2;
2025         ret = pkt_generic_packet(pd, &cgc);
2026         if (ret) {
2027                 pkt_dump_sense(pd, &cgc);
2028                 return ret;
2029         }
2030         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2031         if (size > sizeof(buf))
2032                 size = sizeof(buf);
2033
2034         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2035         cgc.sense = &sense;
2036         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2037         cgc.cmd[1] = 2;
2038         cgc.cmd[2] = 4;
2039         cgc.cmd[8] = size;
2040         ret = pkt_generic_packet(pd, &cgc);
2041         if (ret) {
2042                 pkt_dump_sense(pd, &cgc);
2043                 return ret;
2044         }
2045
2046         if (!(buf[6] & 0x40)) {
2047                 pkt_notice(pd, "disc type is not CD-RW\n");
2048                 return 1;
2049         }
2050         if (!(buf[6] & 0x4)) {
2051                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2052                 return 1;
2053         }
2054
2055         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2056
2057         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2058
2059         /* Info from cdrecord */
2060         switch (st) {
2061                 case 0: /* standard speed */
2062                         *speed = clv_to_speed[sp];
2063                         break;
2064                 case 1: /* high speed */
2065                         *speed = hs_clv_to_speed[sp];
2066                         break;
2067                 case 2: /* ultra high speed */
2068                         *speed = us_clv_to_speed[sp];
2069                         break;
2070                 default:
2071                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2072                         return 1;
2073         }
2074         if (*speed) {
2075                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2076                 return 0;
2077         } else {
2078                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2079                 return 1;
2080         }
2081 }
2082
2083 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2084 {
2085         struct packet_command cgc;
2086         struct request_sense sense;
2087         int ret;
2088
2089         pkt_dbg(2, pd, "Performing OPC\n");
2090
2091         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2092         cgc.sense = &sense;
2093         cgc.timeout = 60*HZ;
2094         cgc.cmd[0] = GPCMD_SEND_OPC;
2095         cgc.cmd[1] = 1;
2096         if ((ret = pkt_generic_packet(pd, &cgc)))
2097                 pkt_dump_sense(pd, &cgc);
2098         return ret;
2099 }
2100
2101 static int pkt_open_write(struct pktcdvd_device *pd)
2102 {
2103         int ret;
2104         unsigned int write_speed, media_write_speed, read_speed;
2105
2106         if ((ret = pkt_probe_settings(pd))) {
2107                 pkt_dbg(2, pd, "failed probe\n");
2108                 return ret;
2109         }
2110
2111         if ((ret = pkt_set_write_settings(pd))) {
2112                 pkt_dbg(1, pd, "failed saving write settings\n");
2113                 return -EIO;
2114         }
2115
2116         pkt_write_caching(pd, USE_WCACHING);
2117
2118         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2119                 write_speed = 16 * 177;
2120         switch (pd->mmc3_profile) {
2121                 case 0x13: /* DVD-RW */
2122                 case 0x1a: /* DVD+RW */
2123                 case 0x12: /* DVD-RAM */
2124                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2125                         break;
2126                 default:
2127                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2128                                 media_write_speed = 16;
2129                         write_speed = min(write_speed, media_write_speed * 177);
2130                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2131                         break;
2132         }
2133         read_speed = write_speed;
2134
2135         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2136                 pkt_dbg(1, pd, "couldn't set write speed\n");
2137                 return -EIO;
2138         }
2139         pd->write_speed = write_speed;
2140         pd->read_speed = read_speed;
2141
2142         if ((ret = pkt_perform_opc(pd))) {
2143                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2144         }
2145
2146         return 0;
2147 }
2148
2149 /*
2150  * called at open time.
2151  */
2152 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2153 {
2154         int ret;
2155         long lba;
2156         struct request_queue *q;
2157
2158         /*
2159          * We need to re-open the cdrom device without O_NONBLOCK to be able
2160          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2161          * so bdget() can't fail.
2162          */
2163         bdget(pd->bdev->bd_dev);
2164         if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2165                 goto out;
2166
2167         if ((ret = pkt_get_last_written(pd, &lba))) {
2168                 pkt_err(pd, "pkt_get_last_written failed\n");
2169                 goto out_putdev;
2170         }
2171
2172         set_capacity(pd->disk, lba << 2);
2173         set_capacity(pd->bdev->bd_disk, lba << 2);
2174         bd_set_size(pd->bdev, (loff_t)lba << 11);
2175
2176         q = bdev_get_queue(pd->bdev);
2177         if (write) {
2178                 if ((ret = pkt_open_write(pd)))
2179                         goto out_putdev;
2180                 /*
2181                  * Some CDRW drives can not handle writes larger than one packet,
2182                  * even if the size is a multiple of the packet size.
2183                  */
2184                 spin_lock_irq(q->queue_lock);
2185                 blk_queue_max_hw_sectors(q, pd->settings.size);
2186                 spin_unlock_irq(q->queue_lock);
2187                 set_bit(PACKET_WRITABLE, &pd->flags);
2188         } else {
2189                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2190                 clear_bit(PACKET_WRITABLE, &pd->flags);
2191         }
2192
2193         if ((ret = pkt_set_segment_merging(pd, q)))
2194                 goto out_putdev;
2195
2196         if (write) {
2197                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2198                         pkt_err(pd, "not enough memory for buffers\n");
2199                         ret = -ENOMEM;
2200                         goto out_putdev;
2201                 }
2202                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2203         }
2204
2205         return 0;
2206
2207 out_putdev:
2208         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2209 out:
2210         return ret;
2211 }
2212
2213 /*
2214  * called when the device is closed. makes sure that the device flushes
2215  * the internal cache before we close.
2216  */
2217 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2218 {
2219         if (flush && pkt_flush_cache(pd))
2220                 pkt_dbg(1, pd, "not flushing cache\n");
2221
2222         pkt_lock_door(pd, 0);
2223
2224         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2225         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2226
2227         pkt_shrink_pktlist(pd);
2228 }
2229
2230 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2231 {
2232         if (dev_minor >= MAX_WRITERS)
2233                 return NULL;
2234         return pkt_devs[dev_minor];
2235 }
2236
2237 static int pkt_open(struct block_device *bdev, fmode_t mode)
2238 {
2239         struct pktcdvd_device *pd = NULL;
2240         int ret;
2241
2242         mutex_lock(&pktcdvd_mutex);
2243         mutex_lock(&ctl_mutex);
2244         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2245         if (!pd) {
2246                 ret = -ENODEV;
2247                 goto out;
2248         }
2249         BUG_ON(pd->refcnt < 0);
2250
2251         pd->refcnt++;
2252         if (pd->refcnt > 1) {
2253                 if ((mode & FMODE_WRITE) &&
2254                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2255                         ret = -EBUSY;
2256                         goto out_dec;
2257                 }
2258         } else {
2259                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2260                 if (ret)
2261                         goto out_dec;
2262                 /*
2263                  * needed here as well, since ext2 (among others) may change
2264                  * the blocksize at mount time
2265                  */
2266                 set_blocksize(bdev, CD_FRAMESIZE);
2267         }
2268
2269         mutex_unlock(&ctl_mutex);
2270         mutex_unlock(&pktcdvd_mutex);
2271         return 0;
2272
2273 out_dec:
2274         pd->refcnt--;
2275 out:
2276         mutex_unlock(&ctl_mutex);
2277         mutex_unlock(&pktcdvd_mutex);
2278         return ret;
2279 }
2280
2281 static void pkt_close(struct gendisk *disk, fmode_t mode)
2282 {
2283         struct pktcdvd_device *pd = disk->private_data;
2284
2285         mutex_lock(&pktcdvd_mutex);
2286         mutex_lock(&ctl_mutex);
2287         pd->refcnt--;
2288         BUG_ON(pd->refcnt < 0);
2289         if (pd->refcnt == 0) {
2290                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2291                 pkt_release_dev(pd, flush);
2292         }
2293         mutex_unlock(&ctl_mutex);
2294         mutex_unlock(&pktcdvd_mutex);
2295 }
2296
2297
2298 static void pkt_end_io_read_cloned(struct bio *bio)
2299 {
2300         struct packet_stacked_data *psd = bio->bi_private;
2301         struct pktcdvd_device *pd = psd->pd;
2302
2303         psd->bio->bi_status = bio->bi_status;
2304         bio_put(bio);
2305         bio_endio(psd->bio);
2306         mempool_free(psd, psd_pool);
2307         pkt_bio_finished(pd);
2308 }
2309
2310 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2311 {
2312         struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, pkt_bio_set);
2313         struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2314
2315         psd->pd = pd;
2316         psd->bio = bio;
2317         bio_set_dev(cloned_bio, pd->bdev);
2318         cloned_bio->bi_private = psd;
2319         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2320         pd->stats.secs_r += bio_sectors(bio);
2321         pkt_queue_bio(pd, cloned_bio);
2322 }
2323
2324 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2325 {
2326         struct pktcdvd_device *pd = q->queuedata;
2327         sector_t zone;
2328         struct packet_data *pkt;
2329         int was_empty, blocked_bio;
2330         struct pkt_rb_node *node;
2331
2332         zone = get_zone(bio->bi_iter.bi_sector, pd);
2333
2334         /*
2335          * If we find a matching packet in state WAITING or READ_WAIT, we can
2336          * just append this bio to that packet.
2337          */
2338         spin_lock(&pd->cdrw.active_list_lock);
2339         blocked_bio = 0;
2340         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2341                 if (pkt->sector == zone) {
2342                         spin_lock(&pkt->lock);
2343                         if ((pkt->state == PACKET_WAITING_STATE) ||
2344                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2345                                 bio_list_add(&pkt->orig_bios, bio);
2346                                 pkt->write_size +=
2347                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2348                                 if ((pkt->write_size >= pkt->frames) &&
2349                                     (pkt->state == PACKET_WAITING_STATE)) {
2350                                         atomic_inc(&pkt->run_sm);
2351                                         wake_up(&pd->wqueue);
2352                                 }
2353                                 spin_unlock(&pkt->lock);
2354                                 spin_unlock(&pd->cdrw.active_list_lock);
2355                                 return;
2356                         } else {
2357                                 blocked_bio = 1;
2358                         }
2359                         spin_unlock(&pkt->lock);
2360                 }
2361         }
2362         spin_unlock(&pd->cdrw.active_list_lock);
2363
2364         /*
2365          * Test if there is enough room left in the bio work queue
2366          * (queue size >= congestion on mark).
2367          * If not, wait till the work queue size is below the congestion off mark.
2368          */
2369         spin_lock(&pd->lock);
2370         if (pd->write_congestion_on > 0
2371             && pd->bio_queue_size >= pd->write_congestion_on) {
2372                 set_bdi_congested(q->backing_dev_info, BLK_RW_ASYNC);
2373                 do {
2374                         spin_unlock(&pd->lock);
2375                         congestion_wait(BLK_RW_ASYNC, HZ);
2376                         spin_lock(&pd->lock);
2377                 } while(pd->bio_queue_size > pd->write_congestion_off);
2378         }
2379         spin_unlock(&pd->lock);
2380
2381         /*
2382          * No matching packet found. Store the bio in the work queue.
2383          */
2384         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2385         node->bio = bio;
2386         spin_lock(&pd->lock);
2387         BUG_ON(pd->bio_queue_size < 0);
2388         was_empty = (pd->bio_queue_size == 0);
2389         pkt_rbtree_insert(pd, node);
2390         spin_unlock(&pd->lock);
2391
2392         /*
2393          * Wake up the worker thread.
2394          */
2395         atomic_set(&pd->scan_queue, 1);
2396         if (was_empty) {
2397                 /* This wake_up is required for correct operation */
2398                 wake_up(&pd->wqueue);
2399         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2400                 /*
2401                  * This wake up is not required for correct operation,
2402                  * but improves performance in some cases.
2403                  */
2404                 wake_up(&pd->wqueue);
2405         }
2406 }
2407
2408 static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
2409 {
2410         struct pktcdvd_device *pd;
2411         char b[BDEVNAME_SIZE];
2412         struct bio *split;
2413
2414         blk_queue_split(q, &bio);
2415
2416         pd = q->queuedata;
2417         if (!pd) {
2418                 pr_err("%s incorrect request queue\n", bio_devname(bio, b));
2419                 goto end_io;
2420         }
2421
2422         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2423                 (unsigned long long)bio->bi_iter.bi_sector,
2424                 (unsigned long long)bio_end_sector(bio));
2425
2426         /*
2427          * Clone READ bios so we can have our own bi_end_io callback.
2428          */
2429         if (bio_data_dir(bio) == READ) {
2430                 pkt_make_request_read(pd, bio);
2431                 return BLK_QC_T_NONE;
2432         }
2433
2434         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2435                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2436                            (unsigned long long)bio->bi_iter.bi_sector);
2437                 goto end_io;
2438         }
2439
2440         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2441                 pkt_err(pd, "wrong bio size\n");
2442                 goto end_io;
2443         }
2444
2445         do {
2446                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2447                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2448
2449                 if (last_zone != zone) {
2450                         BUG_ON(last_zone != zone + pd->settings.size);
2451
2452                         split = bio_split(bio, last_zone -
2453                                           bio->bi_iter.bi_sector,
2454                                           GFP_NOIO, pkt_bio_set);
2455                         bio_chain(split, bio);
2456                 } else {
2457                         split = bio;
2458                 }
2459
2460                 pkt_make_request_write(q, split);
2461         } while (split != bio);
2462
2463         return BLK_QC_T_NONE;
2464 end_io:
2465         bio_io_error(bio);
2466         return BLK_QC_T_NONE;
2467 }
2468
2469 static void pkt_init_queue(struct pktcdvd_device *pd)
2470 {
2471         struct request_queue *q = pd->disk->queue;
2472
2473         blk_queue_make_request(q, pkt_make_request);
2474         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2475         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2476         q->queuedata = pd;
2477 }
2478
2479 static int pkt_seq_show(struct seq_file *m, void *p)
2480 {
2481         struct pktcdvd_device *pd = m->private;
2482         char *msg;
2483         char bdev_buf[BDEVNAME_SIZE];
2484         int states[PACKET_NUM_STATES];
2485
2486         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2487                    bdevname(pd->bdev, bdev_buf));
2488
2489         seq_printf(m, "\nSettings:\n");
2490         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2491
2492         if (pd->settings.write_type == 0)
2493                 msg = "Packet";
2494         else
2495                 msg = "Unknown";
2496         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2497
2498         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2499         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2500
2501         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2502
2503         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2504                 msg = "Mode 1";
2505         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2506                 msg = "Mode 2";
2507         else
2508                 msg = "Unknown";
2509         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2510
2511         seq_printf(m, "\nStatistics:\n");
2512         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2513         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2514         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2515         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2516         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2517
2518         seq_printf(m, "\nMisc:\n");
2519         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2520         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2521         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2522         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2523         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2524         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2525
2526         seq_printf(m, "\nQueue state:\n");
2527         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2528         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2529         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2530
2531         pkt_count_states(pd, states);
2532         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2533                    states[0], states[1], states[2], states[3], states[4], states[5]);
2534
2535         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2536                         pd->write_congestion_off,
2537                         pd->write_congestion_on);
2538         return 0;
2539 }
2540
2541 static int pkt_seq_open(struct inode *inode, struct file *file)
2542 {
2543         return single_open(file, pkt_seq_show, PDE_DATA(inode));
2544 }
2545
2546 static const struct file_operations pkt_proc_fops = {
2547         .open   = pkt_seq_open,
2548         .read   = seq_read,
2549         .llseek = seq_lseek,
2550         .release = single_release
2551 };
2552
2553 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2554 {
2555         int i;
2556         int ret = 0;
2557         char b[BDEVNAME_SIZE];
2558         struct block_device *bdev;
2559
2560         if (pd->pkt_dev == dev) {
2561                 pkt_err(pd, "recursive setup not allowed\n");
2562                 return -EBUSY;
2563         }
2564         for (i = 0; i < MAX_WRITERS; i++) {
2565                 struct pktcdvd_device *pd2 = pkt_devs[i];
2566                 if (!pd2)
2567                         continue;
2568                 if (pd2->bdev->bd_dev == dev) {
2569                         pkt_err(pd, "%s already setup\n",
2570                                 bdevname(pd2->bdev, b));
2571                         return -EBUSY;
2572                 }
2573                 if (pd2->pkt_dev == dev) {
2574                         pkt_err(pd, "can't chain pktcdvd devices\n");
2575                         return -EBUSY;
2576                 }
2577         }
2578
2579         bdev = bdget(dev);
2580         if (!bdev)
2581                 return -ENOMEM;
2582         if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
2583                 WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
2584                 bdput(bdev);
2585                 return -EINVAL;
2586         }
2587         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2588         if (ret)
2589                 return ret;
2590
2591         /* This is safe, since we have a reference from open(). */
2592         __module_get(THIS_MODULE);
2593
2594         pd->bdev = bdev;
2595         set_blocksize(bdev, CD_FRAMESIZE);
2596
2597         pkt_init_queue(pd);
2598
2599         atomic_set(&pd->cdrw.pending_bios, 0);
2600         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2601         if (IS_ERR(pd->cdrw.thread)) {
2602                 pkt_err(pd, "can't start kernel thread\n");
2603                 ret = -ENOMEM;
2604                 goto out_mem;
2605         }
2606
2607         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2608         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2609         return 0;
2610
2611 out_mem:
2612         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2613         /* This is safe: open() is still holding a reference. */
2614         module_put(THIS_MODULE);
2615         return ret;
2616 }
2617
2618 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2619 {
2620         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2621         int ret;
2622
2623         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2624                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2625
2626         mutex_lock(&pktcdvd_mutex);
2627         switch (cmd) {
2628         case CDROMEJECT:
2629                 /*
2630                  * The door gets locked when the device is opened, so we
2631                  * have to unlock it or else the eject command fails.
2632                  */
2633                 if (pd->refcnt == 1)
2634                         pkt_lock_door(pd, 0);
2635                 /* fallthru */
2636         /*
2637          * forward selected CDROM ioctls to CD-ROM, for UDF
2638          */
2639         case CDROMMULTISESSION:
2640         case CDROMREADTOCENTRY:
2641         case CDROM_LAST_WRITTEN:
2642         case CDROM_SEND_PACKET:
2643         case SCSI_IOCTL_SEND_COMMAND:
2644                 ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2645                 break;
2646
2647         default:
2648                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2649                 ret = -ENOTTY;
2650         }
2651         mutex_unlock(&pktcdvd_mutex);
2652
2653         return ret;
2654 }
2655
2656 static unsigned int pkt_check_events(struct gendisk *disk,
2657                                      unsigned int clearing)
2658 {
2659         struct pktcdvd_device *pd = disk->private_data;
2660         struct gendisk *attached_disk;
2661
2662         if (!pd)
2663                 return 0;
2664         if (!pd->bdev)
2665                 return 0;
2666         attached_disk = pd->bdev->bd_disk;
2667         if (!attached_disk || !attached_disk->fops->check_events)
2668                 return 0;
2669         return attached_disk->fops->check_events(attached_disk, clearing);
2670 }
2671
2672 static const struct block_device_operations pktcdvd_ops = {
2673         .owner =                THIS_MODULE,
2674         .open =                 pkt_open,
2675         .release =              pkt_close,
2676         .ioctl =                pkt_ioctl,
2677         .check_events =         pkt_check_events,
2678 };
2679
2680 static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2681 {
2682         return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2683 }
2684
2685 /*
2686  * Set up mapping from pktcdvd device to CD-ROM device.
2687  */
2688 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2689 {
2690         int idx;
2691         int ret = -ENOMEM;
2692         struct pktcdvd_device *pd;
2693         struct gendisk *disk;
2694
2695         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2696
2697         for (idx = 0; idx < MAX_WRITERS; idx++)
2698                 if (!pkt_devs[idx])
2699                         break;
2700         if (idx == MAX_WRITERS) {
2701                 pr_err("max %d writers supported\n", MAX_WRITERS);
2702                 ret = -EBUSY;
2703                 goto out_mutex;
2704         }
2705
2706         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2707         if (!pd)
2708                 goto out_mutex;
2709
2710         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2711                                                   sizeof(struct pkt_rb_node));
2712         if (!pd->rb_pool)
2713                 goto out_mem;
2714
2715         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2716         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2717         spin_lock_init(&pd->cdrw.active_list_lock);
2718
2719         spin_lock_init(&pd->lock);
2720         spin_lock_init(&pd->iosched.lock);
2721         bio_list_init(&pd->iosched.read_queue);
2722         bio_list_init(&pd->iosched.write_queue);
2723         sprintf(pd->name, DRIVER_NAME"%d", idx);
2724         init_waitqueue_head(&pd->wqueue);
2725         pd->bio_queue = RB_ROOT;
2726
2727         pd->write_congestion_on  = write_congestion_on;
2728         pd->write_congestion_off = write_congestion_off;
2729
2730         disk = alloc_disk(1);
2731         if (!disk)
2732                 goto out_mem;
2733         pd->disk = disk;
2734         disk->major = pktdev_major;
2735         disk->first_minor = idx;
2736         disk->fops = &pktcdvd_ops;
2737         disk->flags = GENHD_FL_REMOVABLE;
2738         strcpy(disk->disk_name, pd->name);
2739         disk->devnode = pktcdvd_devnode;
2740         disk->private_data = pd;
2741         disk->queue = blk_alloc_queue(GFP_KERNEL);
2742         if (!disk->queue)
2743                 goto out_mem2;
2744
2745         pd->pkt_dev = MKDEV(pktdev_major, idx);
2746         ret = pkt_new_dev(pd, dev);
2747         if (ret)
2748                 goto out_new_dev;
2749
2750         /* inherit events of the host device */
2751         disk->events = pd->bdev->bd_disk->events;
2752         disk->async_events = pd->bdev->bd_disk->async_events;
2753
2754         add_disk(disk);
2755
2756         pkt_sysfs_dev_new(pd);
2757         pkt_debugfs_dev_new(pd);
2758
2759         pkt_devs[idx] = pd;
2760         if (pkt_dev)
2761                 *pkt_dev = pd->pkt_dev;
2762
2763         mutex_unlock(&ctl_mutex);
2764         return 0;
2765
2766 out_new_dev:
2767         blk_cleanup_queue(disk->queue);
2768 out_mem2:
2769         put_disk(disk);
2770 out_mem:
2771         mempool_destroy(pd->rb_pool);
2772         kfree(pd);
2773 out_mutex:
2774         mutex_unlock(&ctl_mutex);
2775         pr_err("setup of pktcdvd device failed\n");
2776         return ret;
2777 }
2778
2779 /*
2780  * Tear down mapping from pktcdvd device to CD-ROM device.
2781  */
2782 static int pkt_remove_dev(dev_t pkt_dev)
2783 {
2784         struct pktcdvd_device *pd;
2785         int idx;
2786         int ret = 0;
2787
2788         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2789
2790         for (idx = 0; idx < MAX_WRITERS; idx++) {
2791                 pd = pkt_devs[idx];
2792                 if (pd && (pd->pkt_dev == pkt_dev))
2793                         break;
2794         }
2795         if (idx == MAX_WRITERS) {
2796                 pr_debug("dev not setup\n");
2797                 ret = -ENXIO;
2798                 goto out;
2799         }
2800
2801         if (pd->refcnt > 0) {
2802                 ret = -EBUSY;
2803                 goto out;
2804         }
2805         if (!IS_ERR(pd->cdrw.thread))
2806                 kthread_stop(pd->cdrw.thread);
2807
2808         pkt_devs[idx] = NULL;
2809
2810         pkt_debugfs_dev_remove(pd);
2811         pkt_sysfs_dev_remove(pd);
2812
2813         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2814
2815         remove_proc_entry(pd->name, pkt_proc);
2816         pkt_dbg(1, pd, "writer unmapped\n");
2817
2818         del_gendisk(pd->disk);
2819         blk_cleanup_queue(pd->disk->queue);
2820         put_disk(pd->disk);
2821
2822         mempool_destroy(pd->rb_pool);
2823         kfree(pd);
2824
2825         /* This is safe: open() is still holding a reference. */
2826         module_put(THIS_MODULE);
2827
2828 out:
2829         mutex_unlock(&ctl_mutex);
2830         return ret;
2831 }
2832
2833 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2834 {
2835         struct pktcdvd_device *pd;
2836
2837         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2838
2839         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2840         if (pd) {
2841                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2842                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2843         } else {
2844                 ctrl_cmd->dev = 0;
2845                 ctrl_cmd->pkt_dev = 0;
2846         }
2847         ctrl_cmd->num_devices = MAX_WRITERS;
2848
2849         mutex_unlock(&ctl_mutex);
2850 }
2851
2852 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2853 {
2854         void __user *argp = (void __user *)arg;
2855         struct pkt_ctrl_command ctrl_cmd;
2856         int ret = 0;
2857         dev_t pkt_dev = 0;
2858
2859         if (cmd != PACKET_CTRL_CMD)
2860                 return -ENOTTY;
2861
2862         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2863                 return -EFAULT;
2864
2865         switch (ctrl_cmd.command) {
2866         case PKT_CTRL_CMD_SETUP:
2867                 if (!capable(CAP_SYS_ADMIN))
2868                         return -EPERM;
2869                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2870                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2871                 break;
2872         case PKT_CTRL_CMD_TEARDOWN:
2873                 if (!capable(CAP_SYS_ADMIN))
2874                         return -EPERM;
2875                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2876                 break;
2877         case PKT_CTRL_CMD_STATUS:
2878                 pkt_get_status(&ctrl_cmd);
2879                 break;
2880         default:
2881                 return -ENOTTY;
2882         }
2883
2884         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2885                 return -EFAULT;
2886         return ret;
2887 }
2888
2889 #ifdef CONFIG_COMPAT
2890 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2891 {
2892         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2893 }
2894 #endif
2895
2896 static const struct file_operations pkt_ctl_fops = {
2897         .open           = nonseekable_open,
2898         .unlocked_ioctl = pkt_ctl_ioctl,
2899 #ifdef CONFIG_COMPAT
2900         .compat_ioctl   = pkt_ctl_compat_ioctl,
2901 #endif
2902         .owner          = THIS_MODULE,
2903         .llseek         = no_llseek,
2904 };
2905
2906 static struct miscdevice pkt_misc = {
2907         .minor          = MISC_DYNAMIC_MINOR,
2908         .name           = DRIVER_NAME,
2909         .nodename       = "pktcdvd/control",
2910         .fops           = &pkt_ctl_fops
2911 };
2912
2913 static int __init pkt_init(void)
2914 {
2915         int ret;
2916
2917         mutex_init(&ctl_mutex);
2918
2919         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2920                                         sizeof(struct packet_stacked_data));
2921         if (!psd_pool)
2922                 return -ENOMEM;
2923         pkt_bio_set = bioset_create(BIO_POOL_SIZE, 0, 0);
2924         if (!pkt_bio_set) {
2925                 mempool_destroy(psd_pool);
2926                 return -ENOMEM;
2927         }
2928
2929         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2930         if (ret < 0) {
2931                 pr_err("unable to register block device\n");
2932                 goto out2;
2933         }
2934         if (!pktdev_major)
2935                 pktdev_major = ret;
2936
2937         ret = pkt_sysfs_init();
2938         if (ret)
2939                 goto out;
2940
2941         pkt_debugfs_init();
2942
2943         ret = misc_register(&pkt_misc);
2944         if (ret) {
2945                 pr_err("unable to register misc device\n");
2946                 goto out_misc;
2947         }
2948
2949         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2950
2951         return 0;
2952
2953 out_misc:
2954         pkt_debugfs_cleanup();
2955         pkt_sysfs_cleanup();
2956 out:
2957         unregister_blkdev(pktdev_major, DRIVER_NAME);
2958 out2:
2959         mempool_destroy(psd_pool);
2960         bioset_free(pkt_bio_set);
2961         return ret;
2962 }
2963
2964 static void __exit pkt_exit(void)
2965 {
2966         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2967         misc_deregister(&pkt_misc);
2968
2969         pkt_debugfs_cleanup();
2970         pkt_sysfs_cleanup();
2971
2972         unregister_blkdev(pktdev_major, DRIVER_NAME);
2973         mempool_destroy(psd_pool);
2974         bioset_free(pkt_bio_set);
2975 }
2976
2977 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2978 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2979 MODULE_LICENSE("GPL");
2980
2981 module_init(pkt_init);
2982 module_exit(pkt_exit);