drivers/staging/hv/blkvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/device.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/major.h>
  26 #include <linux/delay.h>
  27 #include <linux/hdreg.h>
  28 #include <linux/mutex.h>
  29 #include <linux/slab.h>
  30 #include <scsi/scsi.h>
  31 #include <scsi/scsi_cmnd.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_dbg.h>
  34 #include "osd.h"
  35 #include "logging.h"
  36 #include "version_info.h"
  37 #include "vmbus.h"
  38 #include "storvsc_api.h"
  39
  40
  41 #define BLKVSC_MINORS   64
  42
  43 enum blkvsc_device_type {
  44         UNKNOWN_DEV_TYPE,
  45         HARDDISK_TYPE,
  46         DVD_TYPE,
  47 };
  48
  49 /*
  50  * This request ties the struct request and struct
  51  * blkvsc_request/hv_storvsc_request together A struct request may be
  52  * represented by 1 or more struct blkvsc_request
  53  */
  54 struct blkvsc_request_group {
  55         int outstanding;
  56         int status;
  57         struct list_head blkvsc_req_list;       /* list of blkvsc_requests */
  58 };
  59
  60 struct blkvsc_request {
  61         /* blkvsc_request_group.blkvsc_req_list */
  62         struct list_head req_entry;
  63
  64         /* block_device_context.pending_list */
  65         struct list_head pend_entry;
  66
  67         /* This may be null if we generate a request internally */
  68         struct request *req;
  69
  70         struct block_device_context *dev;
  71
  72         /* The group this request is part of. Maybe null */
  73         struct blkvsc_request_group *group;
  74
  75         wait_queue_head_t wevent;
  76         int cond;
  77
  78         int write;
  79         sector_t sector_start;
  80         unsigned long sector_count;
  81
  82         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
  83         unsigned char cmd_len;
  84         unsigned char cmnd[MAX_COMMAND_SIZE];
  85
  86         struct hv_storvsc_request request;
  87         /*
  88          * !!!DO NOT ADD ANYTHING BELOW HERE!!! Otherwise, memory can overlap,
  89          * because - The extension buffer falls right here and is pointed to by
  90          * request.Extension;
  91          * Which sounds like a horrible idea, who designed this?
  92          */
  93 };
  94
  95 /* Per device structure */
  96 struct block_device_context {
  97         /* point back to our device context */
  98         struct vm_device *device_ctx;
  99         struct kmem_cache *request_pool;
 100         spinlock_t lock;
 101         struct gendisk *gd;
 102         enum blkvsc_device_type device_type;
 103         struct list_head pending_list;
 104
 105         unsigned char device_id[64];
 106         unsigned int device_id_len;
 107         int num_outstanding_reqs;
 108         int shutting_down;
 109         int media_not_present;
 110         unsigned int sector_size;
 111         sector_t capacity;
 112         unsigned int port;
 113         unsigned char path;
 114         unsigned char target;
 115         int users;
 116 };
 117
 118 /* Per driver */
 119 struct blkvsc_driver_context {
 120         /* !! These must be the first 2 fields !! */
 121         /* FIXME this is a bug! */
 122         struct driver_context drv_ctx;
 123         struct storvsc_driver_object drv_obj;
 124 };
 125
 126 /* Static decl */
 127 static DEFINE_MUTEX(blkvsc_mutex);
 128 static int blkvsc_probe(struct device *dev);
 129 static int blkvsc_remove(struct device *device);
 130 static void blkvsc_shutdown(struct device *device);
 131
 132 static int blkvsc_open(struct block_device *bdev,  fmode_t mode);
 133 static int blkvsc_release(struct gendisk *disk, fmode_t mode);
 134 static int blkvsc_media_changed(struct gendisk *gd);
 135 static int blkvsc_revalidate_disk(struct gendisk *gd);
 136 static int blkvsc_getgeo(struct block_device *bd, struct hd_geometry *hg);
 137 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
 138                         unsigned cmd, unsigned long argument);
 139 static void blkvsc_request(struct request_queue *queue);
 140 static void blkvsc_request_completion(struct hv_storvsc_request *request);
 141 static int blkvsc_do_request(struct block_device_context *blkdev,
 142                              struct request *req);
 143 static int blkvsc_submit_request(struct blkvsc_request *blkvsc_req,
 144                 void (*request_completion)(struct hv_storvsc_request *));
 145 static void blkvsc_init_rw(struct blkvsc_request *blkvsc_req);
 146 static void blkvsc_cmd_completion(struct hv_storvsc_request *request);
 147 static int blkvsc_do_inquiry(struct block_device_context *blkdev);
 148 static int blkvsc_do_read_capacity(struct block_device_context *blkdev);
 149 static int blkvsc_do_read_capacity16(struct block_device_context *blkdev);
 150 static int blkvsc_do_flush(struct block_device_context *blkdev);
 151 static int blkvsc_cancel_pending_reqs(struct block_device_context *blkdev);
 152 static int blkvsc_do_pending_reqs(struct block_device_context *blkdev);
 153
 154 static int blkvsc_ringbuffer_size = BLKVSC_RING_BUFFER_SIZE;
 155 module_param(blkvsc_ringbuffer_size, int, S_IRUGO);
 156 MODULE_PARM_DESC(ring_size, "Ring buffer size (in bytes)");
 157
 158 /* The one and only one */
 159 static struct blkvsc_driver_context g_blkvsc_drv;
 160
 161 static const struct block_device_operations block_ops = {
 162         .owner = THIS_MODULE,
 163         .open = blkvsc_open,
 164         .release = blkvsc_release,
 165         .media_changed = blkvsc_media_changed,
 166         .revalidate_disk = blkvsc_revalidate_disk,
 167         .getgeo = blkvsc_getgeo,
 168         .ioctl  = blkvsc_ioctl,
 169 };
 170
 171 /*
 172  * blkvsc_drv_init -  BlkVsc driver initialization.
 173  */
 174 static int blkvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 175 {
 176         struct storvsc_driver_object *storvsc_drv_obj = &g_blkvsc_drv.drv_obj;
 177         struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
 178         int ret;
 179
 180         storvsc_drv_obj->ring_buffer_size = blkvsc_ringbuffer_size;
 181
 182         /* Callback to client driver to complete the initialization */
 183         drv_init(&storvsc_drv_obj->base);
 184
 185         drv_ctx->driver.name = storvsc_drv_obj->base.name;
 186         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->base.deviceType,
 187                sizeof(struct hv_guid));
 188
 189         drv_ctx->probe = blkvsc_probe;
 190         drv_ctx->remove = blkvsc_remove;
 191         drv_ctx->shutdown = blkvsc_shutdown;
 192
 193         /* The driver belongs to vmbus */
 194         ret = vmbus_child_driver_register(drv_ctx);
 195
 196         return ret;
 197 }
 198
 199 static int blkvsc_drv_exit_cb(struct device *dev, void *data)
 200 {
 201         struct device **curr = (struct device **)data;
 202         *curr = dev;
 203         return 1; /* stop iterating */
 204 }
 205
 206 static void blkvsc_drv_exit(void)
 207 {
 208         struct storvsc_driver_object *storvsc_drv_obj = &g_blkvsc_drv.drv_obj;
 209         struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
 210         struct device *current_dev;
 211         int ret;
 212
 213         while (1) {
 214                 current_dev = NULL;
 215
 216                 /* Get the device */
 217                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 218                                              (void *) &current_dev,
 219                                              blkvsc_drv_exit_cb);
 220
 221                 if (ret)
 222                         DPRINT_WARN(BLKVSC_DRV,
 223                                     "driver_for_each_device returned %d", ret);
 224
 225
 226                 if (current_dev == NULL)
 227                         break;
 228
 229                 /* Initiate removal from the top-down */
 230                 device_unregister(current_dev);
 231         }
 232
 233         if (storvsc_drv_obj->base.OnCleanup)
 234                 storvsc_drv_obj->base.OnCleanup(&storvsc_drv_obj->base);
 235
 236         vmbus_child_driver_unregister(drv_ctx);
 237
 238         return;
 239 }
 240
 241 /*
 242  * blkvsc_probe - Add a new device for this driver
 243  */
 244 static int blkvsc_probe(struct device *device)
 245 {
 246         struct driver_context *driver_ctx =
 247                                 driver_to_driver_context(device->driver);
 248         struct blkvsc_driver_context *blkvsc_drv_ctx =
 249                                 (struct blkvsc_driver_context *)driver_ctx;
 250         struct storvsc_driver_object *storvsc_drv_obj =
 251                                 &blkvsc_drv_ctx->drv_obj;
 252         struct vm_device *device_ctx = device_to_vm_device(device);
 253         struct hv_device *device_obj = &device_ctx->device_obj;
 254
 255         struct block_device_context *blkdev = NULL;
 256         struct storvsc_device_info device_info;
 257         int major = 0;
 258         int devnum = 0;
 259         int ret = 0;
 260         static int ide0_registered;
 261         static int ide1_registered;
 262
 263         DPRINT_DBG(BLKVSC_DRV, "blkvsc_probe - enter");
 264
 265         if (!storvsc_drv_obj->base.OnDeviceAdd) {
 266                 DPRINT_ERR(BLKVSC_DRV, "OnDeviceAdd() not set");
 267                 ret = -1;
 268                 goto Cleanup;
 269         }
 270
 271         blkdev = kzalloc(sizeof(struct block_device_context), GFP_KERNEL);
 272         if (!blkdev) {
 273                 ret = -ENOMEM;
 274                 goto Cleanup;
 275         }
 276
 277         INIT_LIST_HEAD(&blkdev->pending_list);
 278
 279         /* Initialize what we can here */
 280         spin_lock_init(&blkdev->lock);
 281
 282         /* ASSERT(sizeof(struct blkvsc_request_group) <= */
 283         /*      sizeof(struct blkvsc_request)); */
 284
 285         blkdev->request_pool = kmem_cache_create(dev_name(&device_ctx->device),
 286                                         sizeof(struct blkvsc_request) +
 287                                         storvsc_drv_obj->request_ext_size, 0,
 288                                         SLAB_HWCACHE_ALIGN, NULL);
 289         if (!blkdev->request_pool) {
 290                 ret = -ENOMEM;
 291                 goto Cleanup;
 292         }
 293
 294
 295         /* Call to the vsc driver to add the device */
 296         ret = storvsc_drv_obj->base.OnDeviceAdd(device_obj, &device_info);
 297         if (ret != 0) {
 298                 DPRINT_ERR(BLKVSC_DRV, "unable to add blkvsc device");
 299                 goto Cleanup;
 300         }
 301
 302         blkdev->device_ctx = device_ctx;
 303         /* this identified the device 0 or 1 */
 304         blkdev->target = device_info.target_id;
 305         /* this identified the ide ctrl 0 or 1 */
 306         blkdev->path = device_info.path_id;
 307
 308         dev_set_drvdata(device, blkdev);
 309
 310         /* Calculate the major and device num */
 311         if (blkdev->path == 0) {
 312                 major = IDE0_MAJOR;
 313                 devnum = blkdev->path + blkdev->target;         /* 0 or 1 */
 314
 315                 if (!ide0_registered) {
 316                         ret = register_blkdev(major, "ide");
 317                         if (ret != 0) {
 318                                 DPRINT_ERR(BLKVSC_DRV,
 319                                            "register_blkdev() failed! ret %d",
 320                                            ret);
 321                                 goto Remove;
 322                         }
 323
 324                         ide0_registered = 1;
 325                 }
 326         } else if (blkdev->path == 1) {
 327                 major = IDE1_MAJOR;
 328                 devnum = blkdev->path + blkdev->target + 1; /* 2 or 3 */
 329
 330                 if (!ide1_registered) {
 331                         ret = register_blkdev(major, "ide");
 332                         if (ret != 0) {
 333                                 DPRINT_ERR(BLKVSC_DRV,
 334                                            "register_blkdev() failed! ret %d",
 335                                            ret);
 336                                 goto Remove;
 337                         }
 338
 339                         ide1_registered = 1;
 340                 }
 341         } else {
 342                 DPRINT_ERR(BLKVSC_DRV, "invalid pathid");
 343                 ret = -1;
 344                 goto Cleanup;
 345         }
 346
 347         DPRINT_INFO(BLKVSC_DRV, "blkvsc registered for major %d!!", major);
 348
 349         blkdev->gd = alloc_disk(BLKVSC_MINORS);
 350         if (!blkdev->gd) {
 351                 DPRINT_ERR(BLKVSC_DRV, "register_blkdev() failed! ret %d", ret);
 352                 ret = -1;
 353                 goto Cleanup;
 354         }
 355
 356         blkdev->gd->queue = blk_init_queue(blkvsc_request, &blkdev->lock);
 357
 358         blk_queue_max_segment_size(blkdev->gd->queue, PAGE_SIZE);
 359         blk_queue_max_segments(blkdev->gd->queue, MAX_MULTIPAGE_BUFFER_COUNT);
 360         blk_queue_segment_boundary(blkdev->gd->queue, PAGE_SIZE-1);
 361         blk_queue_bounce_limit(blkdev->gd->queue, BLK_BOUNCE_ANY);
 362         blk_queue_dma_alignment(blkdev->gd->queue, 511);
 363
 364         blkdev->gd->major = major;
 365         if (devnum == 1 || devnum == 3)
 366                 blkdev->gd->first_minor = BLKVSC_MINORS;
 367         else
 368                 blkdev->gd->first_minor = 0;
 369         blkdev->gd->fops = &block_ops;
 370         blkdev->gd->private_data = blkdev;
 371         blkdev->gd->driverfs_dev = &(blkdev->device_ctx->device);
 372         sprintf(blkdev->gd->disk_name, "hd%c", 'a' + devnum);
 373
 374         blkvsc_do_inquiry(blkdev);
 375         if (blkdev->device_type == DVD_TYPE) {
 376                 set_disk_ro(blkdev->gd, 1);
 377                 blkdev->gd->flags |= GENHD_FL_REMOVABLE;
 378                 blkvsc_do_read_capacity(blkdev);
 379         } else {
 380                 blkvsc_do_read_capacity16(blkdev);
 381         }
 382
 383         set_capacity(blkdev->gd, blkdev->capacity * (blkdev->sector_size/512));
 384         blk_queue_logical_block_size(blkdev->gd->queue, blkdev->sector_size);
 385         /* go! */
 386         add_disk(blkdev->gd);
 387
 388         DPRINT_INFO(BLKVSC_DRV, "%s added!! capacity %lu sector_size %d",
 389                     blkdev->gd->disk_name, (unsigned long)blkdev->capacity,
 390                     blkdev->sector_size);
 391
 392         return ret;
 393
 394 Remove:
 395         storvsc_drv_obj->base.OnDeviceRemove(device_obj);
 396
 397 Cleanup:
 398         if (blkdev) {
 399                 if (blkdev->request_pool) {
 400                         kmem_cache_destroy(blkdev->request_pool);
 401                         blkdev->request_pool = NULL;
 402                 }
 403                 kfree(blkdev);
 404                 blkdev = NULL;
 405         }
 406
 407         return ret;
 408 }
 409
 410 static void blkvsc_shutdown(struct device *device)
 411 {
 412         struct block_device_context *blkdev = dev_get_drvdata(device);
 413         unsigned long flags;
 414
 415         if (!blkdev)
 416                 return;
 417
 418         DPRINT_DBG(BLKVSC_DRV, "blkvsc_shutdown - users %d disk %s\n",
 419                    blkdev->users, blkdev->gd->disk_name);
 420
 421         spin_lock_irqsave(&blkdev->lock, flags);
 422
 423         blkdev->shutting_down = 1;
 424
 425         blk_stop_queue(blkdev->gd->queue);
 426
 427         spin_unlock_irqrestore(&blkdev->lock, flags);
 428
 429         while (blkdev->num_outstanding_reqs) {
 430                 DPRINT_INFO(STORVSC, "waiting for %d requests to complete...",
 431                             blkdev->num_outstanding_reqs);
 432                 udelay(100);
 433         }
 434
 435         blkvsc_do_flush(blkdev);
 436
 437         spin_lock_irqsave(&blkdev->lock, flags);
 438
 439         blkvsc_cancel_pending_reqs(blkdev);
 440
 441         spin_unlock_irqrestore(&blkdev->lock, flags);
 442 }
 443
 444 static int blkvsc_do_flush(struct block_device_context *blkdev)
 445 {
 446         struct blkvsc_request *blkvsc_req;
 447
 448         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_flush()\n");
 449
 450         if (blkdev->device_type != HARDDISK_TYPE)
 451                 return 0;
 452
 453         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 454         if (!blkvsc_req)
 455                 return -ENOMEM;
 456
 457         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 458         init_waitqueue_head(&blkvsc_req->wevent);
 459         blkvsc_req->dev = blkdev;
 460         blkvsc_req->req = NULL;
 461         blkvsc_req->write = 0;
 462
 463         blkvsc_req->request.data_buffer.PfnArray[0] = 0;
 464         blkvsc_req->request.data_buffer.Offset = 0;
 465         blkvsc_req->request.data_buffer.Length = 0;
 466
 467         blkvsc_req->cmnd[0] = SYNCHRONIZE_CACHE;
 468         blkvsc_req->cmd_len = 10;
 469
 470         /*
 471          * Set this here since the completion routine may be invoked and
 472          * completed before we return
 473          */
 474         blkvsc_req->cond = 0;
 475         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 476
 477         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 478
 479         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 480
 481         return 0;
 482 }
 483
 484 /* Do a scsi INQUIRY cmd here to get the device type (ie disk or dvd) */
 485 static int blkvsc_do_inquiry(struct block_device_context *blkdev)
 486 {
 487         struct blkvsc_request *blkvsc_req;
 488         struct page *page_buf;
 489         unsigned char *buf;
 490         unsigned char device_type;
 491
 492         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_inquiry()\n");
 493
 494         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 495         if (!blkvsc_req)
 496                 return -ENOMEM;
 497
 498         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 499         page_buf = alloc_page(GFP_KERNEL);
 500         if (!page_buf) {
 501                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 502                 return -ENOMEM;
 503         }
 504
 505         init_waitqueue_head(&blkvsc_req->wevent);
 506         blkvsc_req->dev = blkdev;
 507         blkvsc_req->req = NULL;
 508         blkvsc_req->write = 0;
 509
 510         blkvsc_req->request.data_buffer.PfnArray[0] = page_to_pfn(page_buf);
 511         blkvsc_req->request.data_buffer.Offset = 0;
 512         blkvsc_req->request.data_buffer.Length = 64;
 513
 514         blkvsc_req->cmnd[0] = INQUIRY;
 515         blkvsc_req->cmnd[1] = 0x1;              /* Get product data */
 516         blkvsc_req->cmnd[2] = 0x83;             /* mode page 83 */
 517         blkvsc_req->cmnd[4] = 64;
 518         blkvsc_req->cmd_len = 6;
 519
 520         /*
 521          * Set this here since the completion routine may be invoked and
 522          * completed before we return
 523          */
 524         blkvsc_req->cond = 0;
 525
 526         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 527
 528         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 529                    blkvsc_req, blkvsc_req->cond);
 530
 531         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 532
 533         buf = kmap(page_buf);
 534
 535         /* print_hex_dump_bytes("", DUMP_PREFIX_NONE, buf, 64); */
 536         /* be to le */
 537         device_type = buf[0] & 0x1F;
 538
 539         if (device_type == 0x0) {
 540                 blkdev->device_type = HARDDISK_TYPE;
 541         } else if (device_type == 0x5) {
 542                 blkdev->device_type = DVD_TYPE;
 543         } else {
 544                 /* TODO: this is currently unsupported device type */
 545                 blkdev->device_type = UNKNOWN_DEV_TYPE;
 546         }
 547
 548         DPRINT_DBG(BLKVSC_DRV, "device type %d\n", device_type);
 549
 550         blkdev->device_id_len = buf[7];
 551         if (blkdev->device_id_len > 64)
 552                 blkdev->device_id_len = 64;
 553
 554         memcpy(blkdev->device_id, &buf[8], blkdev->device_id_len);
 555         /* printk_hex_dump_bytes("", DUMP_PREFIX_NONE, blkdev->device_id,
 556          * blkdev->device_id_len); */
 557
 558         kunmap(page_buf);
 559
 560         __free_page(page_buf);
 561
 562         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 563
 564         return 0;
 565 }
 566
 567 /* Do a scsi READ_CAPACITY cmd here to get the size of the disk */
 568 static int blkvsc_do_read_capacity(struct block_device_context *blkdev)
 569 {
 570         struct blkvsc_request *blkvsc_req;
 571         struct page *page_buf;
 572         unsigned char *buf;
 573         struct scsi_sense_hdr sense_hdr;
 574
 575         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_read_capacity()\n");
 576
 577         blkdev->sector_size = 0;
 578         blkdev->capacity = 0;
 579         blkdev->media_not_present = 0; /* assume a disk is present */
 580
 581         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 582         if (!blkvsc_req)
 583                 return -ENOMEM;
 584
 585         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 586         page_buf = alloc_page(GFP_KERNEL);
 587         if (!page_buf) {
 588                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 589                 return -ENOMEM;
 590         }
 591
 592         init_waitqueue_head(&blkvsc_req->wevent);
 593         blkvsc_req->dev = blkdev;
 594         blkvsc_req->req = NULL;
 595         blkvsc_req->write = 0;
 596
 597         blkvsc_req->request.data_buffer.PfnArray[0] = page_to_pfn(page_buf);
 598         blkvsc_req->request.data_buffer.Offset = 0;
 599         blkvsc_req->request.data_buffer.Length = 8;
 600
 601         blkvsc_req->cmnd[0] = READ_CAPACITY;
 602         blkvsc_req->cmd_len = 16;
 603
 604         /*
 605          * Set this here since the completion routine may be invoked
 606          * and completed before we return
 607          */
 608         blkvsc_req->cond = 0;
 609
 610         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 611
 612         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 613                    blkvsc_req, blkvsc_req->cond);
 614
 615         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 616
 617         /* check error */
 618         if (blkvsc_req->request.status) {
 619                 scsi_normalize_sense(blkvsc_req->sense_buffer,
 620                                      SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 621
 622                 if (sense_hdr.asc == 0x3A) {
 623                         /* Medium not present */
 624                         blkdev->media_not_present = 1;
 625                 }
 626                 return 0;
 627         }
 628         buf = kmap(page_buf);
 629
 630         /* be to le */
 631         blkdev->capacity = ((buf[0] << 24) | (buf[1] << 16) |
 632                             (buf[2] << 8) | buf[3]) + 1;
 633         blkdev->sector_size = (buf[4] << 24) | (buf[5] << 16) |
 634                               (buf[6] << 8) | buf[7];
 635
 636         kunmap(page_buf);
 637
 638         __free_page(page_buf);
 639
 640         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 641
 642         return 0;
 643 }
 644
 645 static int blkvsc_do_read_capacity16(struct block_device_context *blkdev)
 646 {
 647         struct blkvsc_request *blkvsc_req;
 648         struct page *page_buf;
 649         unsigned char *buf;
 650         struct scsi_sense_hdr sense_hdr;
 651
 652         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_read_capacity16()\n");
 653
 654         blkdev->sector_size = 0;
 655         blkdev->capacity = 0;
 656         blkdev->media_not_present = 0; /* assume a disk is present */
 657
 658         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 659         if (!blkvsc_req)
 660                 return -ENOMEM;
 661
 662         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 663         page_buf = alloc_page(GFP_KERNEL);
 664         if (!page_buf) {
 665                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 666                 return -ENOMEM;
 667         }
 668
 669         init_waitqueue_head(&blkvsc_req->wevent);
 670         blkvsc_req->dev = blkdev;
 671         blkvsc_req->req = NULL;
 672         blkvsc_req->write = 0;
 673
 674         blkvsc_req->request.data_buffer.PfnArray[0] = page_to_pfn(page_buf);
 675         blkvsc_req->request.data_buffer.Offset = 0;
 676         blkvsc_req->request.data_buffer.Length = 12;
 677
 678         blkvsc_req->cmnd[0] = 0x9E; /* READ_CAPACITY16; */
 679         blkvsc_req->cmd_len = 16;
 680
 681         /*
 682          * Set this here since the completion routine may be invoked
 683          * and completed before we return
 684          */
 685         blkvsc_req->cond = 0;
 686
 687         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 688
 689         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 690                    blkvsc_req, blkvsc_req->cond);
 691
 692         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 693
 694         /* check error */
 695         if (blkvsc_req->request.status) {
 696                 scsi_normalize_sense(blkvsc_req->sense_buffer,
 697                                      SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 698                 if (sense_hdr.asc == 0x3A) {
 699                         /* Medium not present */
 700                         blkdev->media_not_present = 1;
 701                 }
 702                 return 0;
 703         }
 704         buf = kmap(page_buf);
 705
 706         /* be to le */
 707         blkdev->capacity = be64_to_cpu(*(unsigned long long *) &buf[0]) + 1;
 708         blkdev->sector_size = be32_to_cpu(*(unsigned int *)&buf[8]);
 709
 710 #if 0
 711         blkdev->capacity = ((buf[0] << 24) | (buf[1] << 16) |
 712                             (buf[2] << 8) | buf[3]) + 1;
 713         blkdev->sector_size = (buf[4] << 24) | (buf[5] << 16) |
 714                               (buf[6] << 8) | buf[7];
 715 #endif
 716
 717         kunmap(page_buf);
 718
 719         __free_page(page_buf);
 720
 721         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 722
 723         return 0;
 724 }
 725
 726 /*
 727  * blkvsc_remove() - Callback when our device is removed
 728  */
 729 static int blkvsc_remove(struct device *device)
 730 {
 731         struct driver_context *driver_ctx =
 732                                 driver_to_driver_context(device->driver);
 733         struct blkvsc_driver_context *blkvsc_drv_ctx =
 734                                 (struct blkvsc_driver_context *)driver_ctx;
 735         struct storvsc_driver_object *storvsc_drv_obj =
 736                                 &blkvsc_drv_ctx->drv_obj;
 737         struct vm_device *device_ctx = device_to_vm_device(device);
 738         struct hv_device *device_obj = &device_ctx->device_obj;
 739         struct block_device_context *blkdev = dev_get_drvdata(device);
 740         unsigned long flags;
 741         int ret;
 742
 743         DPRINT_DBG(BLKVSC_DRV, "blkvsc_remove()\n");
 744
 745         if (!storvsc_drv_obj->base.OnDeviceRemove)
 746                 return -1;
 747
 748         /*
 749          * Call to the vsc driver to let it know that the device is being
 750          * removed
 751          */
 752         ret = storvsc_drv_obj->base.OnDeviceRemove(device_obj);
 753         if (ret != 0) {
 754                 /* TODO: */
 755                 DPRINT_ERR(BLKVSC_DRV,
 756                            "unable to remove blkvsc device (ret %d)", ret);
 757         }
 758
 759         /* Get to a known state */
 760         spin_lock_irqsave(&blkdev->lock, flags);
 761
 762         blkdev->shutting_down = 1;
 763
 764         blk_stop_queue(blkdev->gd->queue);
 765
 766         spin_unlock_irqrestore(&blkdev->lock, flags);
 767
 768         while (blkdev->num_outstanding_reqs) {
 769                 DPRINT_INFO(STORVSC, "waiting for %d requests to complete...",
 770                             blkdev->num_outstanding_reqs);
 771                 udelay(100);
 772         }
 773
 774         blkvsc_do_flush(blkdev);
 775
 776         spin_lock_irqsave(&blkdev->lock, flags);
 777
 778         blkvsc_cancel_pending_reqs(blkdev);
 779
 780         spin_unlock_irqrestore(&blkdev->lock, flags);
 781
 782         blk_cleanup_queue(blkdev->gd->queue);
 783
 784         del_gendisk(blkdev->gd);
 785
 786         kmem_cache_destroy(blkdev->request_pool);
 787
 788         kfree(blkdev);
 789
 790         return ret;
 791 }
 792
 793 static void blkvsc_init_rw(struct blkvsc_request *blkvsc_req)
 794 {
 795         /* ASSERT(blkvsc_req->req); */
 796         /* ASSERT(blkvsc_req->sector_count <= (MAX_MULTIPAGE_BUFFER_COUNT*8)); */
 797
 798         blkvsc_req->cmd_len = 16;
 799
 800         if (blkvsc_req->sector_start > 0xffffffff) {
 801                 if (rq_data_dir(blkvsc_req->req)) {
 802                         blkvsc_req->write = 1;
 803                         blkvsc_req->cmnd[0] = WRITE_16;
 804                 } else {
 805                         blkvsc_req->write = 0;
 806                         blkvsc_req->cmnd[0] = READ_16;
 807                 }
 808
 809                 blkvsc_req->cmnd[1] |=
 810                         (blkvsc_req->req->cmd_flags & REQ_FUA) ? 0x8 : 0;
 811
 812                 *(unsigned long long *)&blkvsc_req->cmnd[2] =
 813                                 cpu_to_be64(blkvsc_req->sector_start);
 814                 *(unsigned int *)&blkvsc_req->cmnd[10] =
 815                                 cpu_to_be32(blkvsc_req->sector_count);
 816         } else if ((blkvsc_req->sector_count > 0xff) ||
 817                    (blkvsc_req->sector_start > 0x1fffff)) {
 818                 if (rq_data_dir(blkvsc_req->req)) {
 819                         blkvsc_req->write = 1;
 820                         blkvsc_req->cmnd[0] = WRITE_10;
 821                 } else {
 822                         blkvsc_req->write = 0;
 823                         blkvsc_req->cmnd[0] = READ_10;
 824                 }
 825
 826                 blkvsc_req->cmnd[1] |=
 827                         (blkvsc_req->req->cmd_flags & REQ_FUA) ? 0x8 : 0;
 828
 829                 *(unsigned int *)&blkvsc_req->cmnd[2] =
 830                                 cpu_to_be32(blkvsc_req->sector_start);
 831                 *(unsigned short *)&blkvsc_req->cmnd[7] =
 832                                 cpu_to_be16(blkvsc_req->sector_count);
 833         } else {
 834                 if (rq_data_dir(blkvsc_req->req)) {
 835                         blkvsc_req->write = 1;
 836                         blkvsc_req->cmnd[0] = WRITE_6;
 837                 } else {
 838                         blkvsc_req->write = 0;
 839                         blkvsc_req->cmnd[0] = READ_6;
 840                 }
 841
 842                 *(unsigned int *)&blkvsc_req->cmnd[1] =
 843                                 cpu_to_be32(blkvsc_req->sector_start) >> 8;
 844                 blkvsc_req->cmnd[1] &= 0x1f;
 845                 blkvsc_req->cmnd[4] = (unsigned char)blkvsc_req->sector_count;
 846         }
 847 }
 848
 849 static int blkvsc_submit_request(struct blkvsc_request *blkvsc_req,
 850                         void (*request_completion)(struct hv_storvsc_request *))
 851 {
 852         struct block_device_context *blkdev = blkvsc_req->dev;
 853         struct vm_device *device_ctx = blkdev->device_ctx;
 854         struct driver_context *driver_ctx =
 855                         driver_to_driver_context(device_ctx->device.driver);
 856         struct blkvsc_driver_context *blkvsc_drv_ctx =
 857                         (struct blkvsc_driver_context *)driver_ctx;
 858         struct storvsc_driver_object *storvsc_drv_obj =
 859                         &blkvsc_drv_ctx->drv_obj;
 860         struct hv_storvsc_request *storvsc_req;
 861         int ret;
 862
 863         DPRINT_DBG(BLKVSC_DRV, "blkvsc_submit_request() - "
 864                    "req %p type %s start_sector %lu count %ld offset %d "
 865                    "len %d\n", blkvsc_req,
 866                    (blkvsc_req->write) ? "WRITE" : "READ",
 867                    (unsigned long) blkvsc_req->sector_start,
 868                    blkvsc_req->sector_count,
 869                    blkvsc_req->request.data_buffer.Offset,
 870                    blkvsc_req->request.data_buffer.Length);
 871 #if 0
 872         for (i = 0; i < (blkvsc_req->request.data_buffer.Length >> 12); i++) {
 873                 DPRINT_DBG(BLKVSC_DRV, "blkvsc_submit_request() - "
 874                            "req %p pfn[%d] %llx\n",
 875                            blkvsc_req, i,
 876                            blkvsc_req->request.data_buffer.PfnArray[i]);
 877         }
 878 #endif
 879
 880         storvsc_req = &blkvsc_req->request;
 881         storvsc_req->extension = (void *)((unsigned long)blkvsc_req +
 882                                           sizeof(struct blkvsc_request));
 883
 884         storvsc_req->type = blkvsc_req->write ? WRITE_TYPE : READ_TYPE;
 885
 886         storvsc_req->on_io_completion = request_completion;
 887         storvsc_req->context = blkvsc_req;
 888
 889         storvsc_req->host = blkdev->port;
 890         storvsc_req->bus = blkdev->path;
 891         storvsc_req->target_id = blkdev->target;
 892         storvsc_req->lun_id = 0;         /* this is not really used at all */
 893
 894         storvsc_req->cdb_len = blkvsc_req->cmd_len;
 895         storvsc_req->cdb = blkvsc_req->cmnd;
 896
 897         storvsc_req->sense_buffer = blkvsc_req->sense_buffer;
 898         storvsc_req->sense_buffer_size = SCSI_SENSE_BUFFERSIZE;
 899
 900         ret = storvsc_drv_obj->on_io_request(&blkdev->device_ctx->device_obj,
 901                                            &blkvsc_req->request);
 902         if (ret == 0)
 903                 blkdev->num_outstanding_reqs++;
 904
 905         return ret;
 906 }
 907
 908 /*
 909  * We break the request into 1 or more blkvsc_requests and submit
 910  * them.  If we cant submit them all, we put them on the
 911  * pending_list. The blkvsc_request() will work on the pending_list.
 912  */
 913 static int blkvsc_do_request(struct block_device_context *blkdev,
 914                              struct request *req)
 915 {
 916         struct bio *bio = NULL;
 917         struct bio_vec *bvec = NULL;
 918         struct bio_vec *prev_bvec = NULL;
 919         struct blkvsc_request *blkvsc_req = NULL;
 920         struct blkvsc_request *tmp;
 921         int databuf_idx = 0;
 922         int seg_idx = 0;
 923         sector_t start_sector;
 924         unsigned long num_sectors = 0;
 925         int ret = 0;
 926         int pending = 0;
 927         struct blkvsc_request_group *group = NULL;
 928
 929         DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p sect %lu\n", blkdev, req,
 930                   (unsigned long)blk_rq_pos(req));
 931
 932         /* Create a group to tie req to list of blkvsc_reqs */
 933         group = kmem_cache_alloc(blkdev->request_pool, GFP_ATOMIC);
 934         if (!group)
 935                 return -ENOMEM;
 936
 937         INIT_LIST_HEAD(&group->blkvsc_req_list);
 938         group->outstanding = group->status = 0;
 939
 940         start_sector = blk_rq_pos(req);
 941
 942         /* foreach bio in the request */
 943         if (req->bio) {
 944                 for (bio = req->bio; bio; bio = bio->bi_next) {
 945                         /*
 946                          * Map this bio into an existing or new storvsc request
 947                          */
 948                         bio_for_each_segment(bvec, bio, seg_idx) {
 949                                 DPRINT_DBG(BLKVSC_DRV, "bio_for_each_segment() "
 950                                            "- req %p bio %p bvec %p seg_idx %d "
 951                                            "databuf_idx %d\n", req, bio, bvec,
 952                                            seg_idx, databuf_idx);
 953
 954                                 /* Get a new storvsc request */
 955                                 /* 1st-time */
 956                                 if ((!blkvsc_req) ||
 957                                     (databuf_idx >= MAX_MULTIPAGE_BUFFER_COUNT)
 958                                     /* hole at the begin of page */
 959                                     || (bvec->bv_offset != 0) ||
 960                                     /* hold at the end of page */
 961                                     (prev_bvec &&
 962                                      (prev_bvec->bv_len != PAGE_SIZE))) {
 963                                         /* submit the prev one */
 964                                         if (blkvsc_req) {
 965                                                 blkvsc_req->sector_start = start_sector;
 966                                                 sector_div(blkvsc_req->sector_start, (blkdev->sector_size >> 9));
 967
 968                                                 blkvsc_req->sector_count = num_sectors / (blkdev->sector_size >> 9);
 969                                                 blkvsc_init_rw(blkvsc_req);
 970                                         }
 971
 972                                         /*
 973                                          * Create new blkvsc_req to represent
 974                                          * the current bvec
 975                                          */
 976                                         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_ATOMIC);
 977                                         if (!blkvsc_req) {
 978                                                 /* free up everything */
 979                                                 list_for_each_entry_safe(
 980                                                         blkvsc_req, tmp,
 981                                                         &group->blkvsc_req_list,
 982                                                         req_entry) {
 983                                                         list_del(&blkvsc_req->req_entry);
 984                                                         kmem_cache_free(blkdev->request_pool, blkvsc_req);
 985                                                 }
 986
 987                                                 kmem_cache_free(blkdev->request_pool, group);
 988                                                 return -ENOMEM;
 989                                         }
 990
 991                                         memset(blkvsc_req, 0,
 992                                                sizeof(struct blkvsc_request));
 993
 994                                         blkvsc_req->dev = blkdev;
 995                                         blkvsc_req->req = req;
 996                                         blkvsc_req->request.data_buffer.Offset
 997                                                 = bvec->bv_offset;
 998                                         blkvsc_req->request.data_buffer.Length
 999                                                 = 0;
1000
1001                                         /* Add to the group */
1002                                         blkvsc_req->group = group;
1003                                         blkvsc_req->group->outstanding++;
1004                                         list_add_tail(&blkvsc_req->req_entry,
1005                                                 &blkvsc_req->group->blkvsc_req_list);
1006
1007                                         start_sector += num_sectors;
1008                                         num_sectors = 0;
1009                                         databuf_idx = 0;
1010                                 }
1011
1012                                 /* Add the curr bvec/segment to the curr blkvsc_req */
1013                                 blkvsc_req->request.data_buffer.
1014                                         PfnArray[databuf_idx]
1015                                                 = page_to_pfn(bvec->bv_page);
1016                                 blkvsc_req->request.data_buffer.Length
1017                                         += bvec->bv_len;
1018
1019                                 prev_bvec = bvec;
1020
1021                                 databuf_idx++;
1022                                 num_sectors += bvec->bv_len >> 9;
1023
1024                         } /* bio_for_each_segment */
1025
1026                 } /* rq_for_each_bio */
1027         }
1028
1029         /* Handle the last one */
1030         if (blkvsc_req) {
1031                 DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p group %p count %d\n",
1032                            blkdev, req, blkvsc_req->group,
1033                            blkvsc_req->group->outstanding);
1034
1035                 blkvsc_req->sector_start = start_sector;
1036                 sector_div(blkvsc_req->sector_start,
1037                            (blkdev->sector_size >> 9));
1038
1039                 blkvsc_req->sector_count = num_sectors /
1040                                            (blkdev->sector_size >> 9);
1041
1042                 blkvsc_init_rw(blkvsc_req);
1043         }
1044
1045         list_for_each_entry(blkvsc_req, &group->blkvsc_req_list, req_entry) {
1046                 if (pending) {
1047                         DPRINT_DBG(BLKVSC_DRV, "adding blkvsc_req to "
1048                                    "pending_list - blkvsc_req %p start_sect %lu"
1049                                    " sect_count %ld (%lu %ld)\n", blkvsc_req,
1050                                    (unsigned long)blkvsc_req->sector_start,
1051                                    blkvsc_req->sector_count,
1052                                    (unsigned long)start_sector,
1053                                    (unsigned long)num_sectors);
1054
1055                         list_add_tail(&blkvsc_req->pend_entry,
1056                                       &blkdev->pending_list);
1057                 } else {
1058                         ret = blkvsc_submit_request(blkvsc_req,
1059                                                     blkvsc_request_completion);
1060                         if (ret == -1) {
1061                                 pending = 1;
1062                                 list_add_tail(&blkvsc_req->pend_entry,
1063                                               &blkdev->pending_list);
1064                         }
1065
1066                         DPRINT_DBG(BLKVSC_DRV, "submitted blkvsc_req %p "
1067                                    "start_sect %lu sect_count %ld (%lu %ld) "
1068                                    "ret %d\n", blkvsc_req,
1069                                    (unsigned long)blkvsc_req->sector_start,
1070                                    blkvsc_req->sector_count,
1071                                    (unsigned long)start_sector,
1072                                    num_sectors, ret);
1073                 }
1074         }
1075
1076         return pending;
1077 }
1078
1079 static void blkvsc_cmd_completion(struct hv_storvsc_request *request)
1080 {
1081         struct blkvsc_request *blkvsc_req =
1082                         (struct blkvsc_request *)request->context;
1083         struct block_device_context *blkdev =
1084                         (struct block_device_context *)blkvsc_req->dev;
1085         struct scsi_sense_hdr sense_hdr;
1086
1087         DPRINT_DBG(BLKVSC_DRV, "blkvsc_cmd_completion() - req %p\n",
1088                    blkvsc_req);
1089
1090         blkdev->num_outstanding_reqs--;
1091
1092         if (blkvsc_req->request.status)
1093                 if (scsi_normalize_sense(blkvsc_req->sense_buffer,
1094                                          SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1095                         scsi_print_sense_hdr("blkvsc", &sense_hdr);
1096
1097         blkvsc_req->cond = 1;
1098         wake_up_interruptible(&blkvsc_req->wevent);
1099 }
1100
1101 static void blkvsc_request_completion(struct hv_storvsc_request *request)
1102 {
1103         struct blkvsc_request *blkvsc_req =
1104                         (struct blkvsc_request *)request->context;
1105         struct block_device_context *blkdev =
1106                         (struct block_device_context *)blkvsc_req->dev;
1107         unsigned long flags;
1108         struct blkvsc_request *comp_req, *tmp;
1109
1110         /* ASSERT(blkvsc_req->group); */
1111
1112         DPRINT_DBG(BLKVSC_DRV, "blkdev %p blkvsc_req %p group %p type %s "
1113                    "sect_start %lu sect_count %ld len %d group outstd %d "
1114                    "total outstd %d\n",
1115                    blkdev, blkvsc_req, blkvsc_req->group,
1116                    (blkvsc_req->write) ? "WRITE" : "READ",
1117                    (unsigned long)blkvsc_req->sector_start,
1118                    blkvsc_req->sector_count,
1119                    blkvsc_req->request.data_buffer.Length,
1120                    blkvsc_req->group->outstanding,
1121                    blkdev->num_outstanding_reqs);
1122
1123         spin_lock_irqsave(&blkdev->lock, flags);
1124
1125         blkdev->num_outstanding_reqs--;
1126         blkvsc_req->group->outstanding--;
1127
1128         /*
1129          * Only start processing when all the blkvsc_reqs are
1130          * completed. This guarantees no out-of-order blkvsc_req
1131          * completion when calling end_that_request_first()
1132          */
1133         if (blkvsc_req->group->outstanding == 0) {
1134                 list_for_each_entry_safe(comp_req, tmp,
1135                                          &blkvsc_req->group->blkvsc_req_list,
1136                                          req_entry) {
1137                         DPRINT_DBG(BLKVSC_DRV, "completing blkvsc_req %p "
1138                                    "sect_start %lu sect_count %ld\n",
1139                                    comp_req,
1140                                    (unsigned long)comp_req->sector_start,
1141                                    comp_req->sector_count);
1142
1143                         list_del(&comp_req->req_entry);
1144
1145                         if (!__blk_end_request(comp_req->req,
1146                                 (!comp_req->request.status ? 0 : -EIO),
1147                                 comp_req->sector_count * blkdev->sector_size)) {
1148                                 /*
1149                                  * All the sectors have been xferred ie the
1150                                  * request is done
1151                                  */
1152                                 DPRINT_DBG(BLKVSC_DRV, "req %p COMPLETED\n",
1153                                            comp_req->req);
1154                                 kmem_cache_free(blkdev->request_pool,
1155                                                 comp_req->group);
1156                         }
1157
1158                         kmem_cache_free(blkdev->request_pool, comp_req);
1159                 }
1160
1161                 if (!blkdev->shutting_down) {
1162                         blkvsc_do_pending_reqs(blkdev);
1163                         blk_start_queue(blkdev->gd->queue);
1164                         blkvsc_request(blkdev->gd->queue);
1165                 }
1166         }
1167
1168         spin_unlock_irqrestore(&blkdev->lock, flags);
1169 }
1170
1171 static int blkvsc_cancel_pending_reqs(struct block_device_context *blkdev)
1172 {
1173         struct blkvsc_request *pend_req, *tmp;
1174         struct blkvsc_request *comp_req, *tmp2;
1175
1176         int ret = 0;
1177
1178         DPRINT_DBG(BLKVSC_DRV, "blkvsc_cancel_pending_reqs()");
1179
1180         /* Flush the pending list first */
1181         list_for_each_entry_safe(pend_req, tmp, &blkdev->pending_list,
1182                                  pend_entry) {
1183                 /*
1184                  * The pend_req could be part of a partially completed
1185                  * request. If so, complete those req first until we
1186                  * hit the pend_req
1187                  */
1188                 list_for_each_entry_safe(comp_req, tmp2,
1189                                          &pend_req->group->blkvsc_req_list,
1190                                          req_entry) {
1191                         DPRINT_DBG(BLKVSC_DRV, "completing blkvsc_req %p "
1192                                    "sect_start %lu sect_count %ld\n",
1193                                    comp_req,
1194                                    (unsigned long) comp_req->sector_start,
1195                                    comp_req->sector_count);
1196
1197                         if (comp_req == pend_req)
1198                                 break;
1199
1200                         list_del(&comp_req->req_entry);
1201
1202                         if (comp_req->req) {
1203                                 ret = __blk_end_request(comp_req->req,
1204                                         (!comp_req->request.status ? 0 : -EIO),
1205                                         comp_req->sector_count *
1206                                         blkdev->sector_size);
1207
1208                                 /* FIXME: shouldn't this do more than return? */
1209                                 if (ret)
1210                                         goto out;
1211                         }
1212
1213                         kmem_cache_free(blkdev->request_pool, comp_req);
1214                 }
1215
1216                 DPRINT_DBG(BLKVSC_DRV, "cancelling pending request - %p\n",
1217                            pend_req);
1218
1219                 list_del(&pend_req->pend_entry);
1220
1221                 list_del(&pend_req->req_entry);
1222
1223                 if (comp_req->req) {
1224                         if (!__blk_end_request(pend_req->req, -EIO,
1225                                                pend_req->sector_count *
1226                                                blkdev->sector_size)) {
1227                                 /*
1228                                  * All the sectors have been xferred ie the
1229                                  * request is done
1230                                  */
1231                                 DPRINT_DBG(BLKVSC_DRV,
1232                                            "blkvsc_cancel_pending_reqs() - "
1233                                            "req %p COMPLETED\n", pend_req->req);
1234                                 kmem_cache_free(blkdev->request_pool,
1235                                                 pend_req->group);
1236                         }
1237                 }
1238
1239                 kmem_cache_free(blkdev->request_pool, pend_req);
1240         }
1241
1242 out:
1243         return ret;
1244 }
1245
1246 static int blkvsc_do_pending_reqs(struct block_device_context *blkdev)
1247 {
1248         struct blkvsc_request *pend_req, *tmp;
1249         int ret = 0;
1250
1251         /* Flush the pending list first */
1252         list_for_each_entry_safe(pend_req, tmp, &blkdev->pending_list,
1253                                  pend_entry) {
1254                 DPRINT_DBG(BLKVSC_DRV, "working off pending_list - %p\n",
1255                            pend_req);
1256
1257                 ret = blkvsc_submit_request(pend_req,
1258                                             blkvsc_request_completion);
1259                 if (ret != 0)
1260                         break;
1261                 else
1262                         list_del(&pend_req->pend_entry);
1263         }
1264
1265         return ret;
1266 }
1267
1268 static void blkvsc_request(struct request_queue *queue)
1269 {
1270         struct block_device_context *blkdev = NULL;
1271         struct request *req;
1272         int ret = 0;
1273
1274         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1275         while ((req = blk_peek_request(queue)) != NULL) {
1276                 DPRINT_DBG(BLKVSC_DRV, "- req %p\n", req);
1277
1278                 blkdev = req->rq_disk->private_data;
1279                 if (blkdev->shutting_down || req->cmd_type != REQ_TYPE_FS ||
1280                     blkdev->media_not_present) {
1281                         __blk_end_request_cur(req, 0);
1282                         continue;
1283                 }
1284
1285                 ret = blkvsc_do_pending_reqs(blkdev);
1286
1287                 if (ret != 0) {
1288                         DPRINT_DBG(BLKVSC_DRV,
1289                                    "- stop queue - pending_list not empty\n");
1290                         blk_stop_queue(queue);
1291                         break;
1292                 }
1293
1294                 blk_start_request(req);
1295
1296                 ret = blkvsc_do_request(blkdev, req);
1297                 if (ret > 0) {
1298                         DPRINT_DBG(BLKVSC_DRV, "- stop queue - no room\n");
1299                         blk_stop_queue(queue);
1300                         break;
1301                 } else if (ret < 0) {
1302                         DPRINT_DBG(BLKVSC_DRV, "- stop queue - no mem\n");
1303                         blk_requeue_request(queue, req);
1304                         blk_stop_queue(queue);
1305                         break;
1306                 }
1307         }
1308 }
1309
1310 static int blkvsc_open(struct block_device *bdev, fmode_t mode)
1311 {
1312         struct block_device_context *blkdev = bdev->bd_disk->private_data;
1313
1314         DPRINT_DBG(BLKVSC_DRV, "- users %d disk %s\n", blkdev->users,
1315                    blkdev->gd->disk_name);
1316
1317         mutex_lock(&blkvsc_mutex);
1318         spin_lock(&blkdev->lock);
1319
1320         if (!blkdev->users && blkdev->device_type == DVD_TYPE) {
1321                 spin_unlock(&blkdev->lock);
1322                 check_disk_change(bdev);
1323                 spin_lock(&blkdev->lock);
1324         }
1325
1326         blkdev->users++;
1327
1328         spin_unlock(&blkdev->lock);
1329         mutex_unlock(&blkvsc_mutex);
1330         return 0;
1331 }
1332
1333 static int blkvsc_release(struct gendisk *disk, fmode_t mode)
1334 {
1335         struct block_device_context *blkdev = disk->private_data;
1336
1337         DPRINT_DBG(BLKVSC_DRV, "- users %d disk %s\n", blkdev->users,
1338                    blkdev->gd->disk_name);
1339
1340         mutex_lock(&blkvsc_mutex);
1341         spin_lock(&blkdev->lock);
1342         if (blkdev->users == 1) {
1343                 spin_unlock(&blkdev->lock);
1344                 blkvsc_do_flush(blkdev);
1345                 spin_lock(&blkdev->lock);
1346         }
1347
1348         blkdev->users--;
1349
1350         spin_unlock(&blkdev->lock);
1351         mutex_unlock(&blkvsc_mutex);
1352         return 0;
1353 }
1354
1355 static int blkvsc_media_changed(struct gendisk *gd)
1356 {
1357         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1358         return 1;
1359 }
1360
1361 static int blkvsc_revalidate_disk(struct gendisk *gd)
1362 {
1363         struct block_device_context *blkdev = gd->private_data;
1364
1365         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1366
1367         if (blkdev->device_type == DVD_TYPE) {
1368                 blkvsc_do_read_capacity(blkdev);
1369                 set_capacity(blkdev->gd, blkdev->capacity *
1370                             (blkdev->sector_size/512));
1371                 blk_queue_logical_block_size(gd->queue, blkdev->sector_size);
1372         }
1373         return 0;
1374 }
1375
1376 static int blkvsc_getgeo(struct block_device *bd, struct hd_geometry *hg)
1377 {
1378         sector_t total_sectors = get_capacity(bd->bd_disk);
1379         sector_t cylinder_times_heads = 0;
1380         sector_t temp = 0;
1381
1382         int sectors_per_track = 0;
1383         int heads = 0;
1384         int cylinders = 0;
1385         int rem = 0;
1386
1387         if (total_sectors > (65535 * 16 * 255))
1388                 total_sectors = (65535 * 16 * 255);
1389
1390         if (total_sectors >= (65535 * 16 * 63)) {
1391                 sectors_per_track = 255;
1392                 heads = 16;
1393
1394                 cylinder_times_heads = total_sectors;
1395                 /* sector_div stores the quotient in cylinder_times_heads */
1396                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1397         } else {
1398                 sectors_per_track = 17;
1399
1400                 cylinder_times_heads = total_sectors;
1401                 /* sector_div stores the quotient in cylinder_times_heads */
1402                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1403
1404                 temp = cylinder_times_heads + 1023;
1405                 /* sector_div stores the quotient in temp */
1406                 rem = sector_div(temp, 1024);
1407
1408                 heads = temp;
1409
1410                 if (heads < 4)
1411                         heads = 4;
1412
1413
1414                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
1415                         sectors_per_track = 31;
1416                         heads = 16;
1417
1418                         cylinder_times_heads = total_sectors;
1419                         /*
1420                          * sector_div stores the quotient in
1421                          * cylinder_times_heads
1422                          */
1423                         rem = sector_div(cylinder_times_heads,
1424                                          sectors_per_track);
1425                 }
1426
1427                 if (cylinder_times_heads >= (heads * 1024)) {
1428                         sectors_per_track = 63;
1429                         heads = 16;
1430
1431                         cylinder_times_heads = total_sectors;
1432                         /*
1433                          * sector_div stores the quotient in
1434                          * cylinder_times_heads
1435                          */
1436                         rem = sector_div(cylinder_times_heads,
1437                                          sectors_per_track);
1438                 }
1439         }
1440
1441         temp = cylinder_times_heads;
1442         /* sector_div stores the quotient in temp */
1443         rem = sector_div(temp, heads);
1444         cylinders = temp;
1445
1446         hg->heads = heads;
1447         hg->sectors = sectors_per_track;
1448         hg->cylinders = cylinders;
1449
1450         DPRINT_INFO(BLKVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
1451                     sectors_per_track);
1452
1453     return 0;
1454 }
1455
1456 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
1457                         unsigned cmd, unsigned long argument)
1458 {
1459 /*      struct block_device_context *blkdev = bd->bd_disk->private_data; */
1460         int ret;
1461
1462         switch (cmd) {
1463         /*
1464          * TODO: I think there is certain format for HDIO_GET_IDENTITY rather
1465          * than just a GUID. Commented it out for now.
1466          */
1467 #if 0
1468         case HDIO_GET_IDENTITY:
1469                 DPRINT_INFO(BLKVSC_DRV, "HDIO_GET_IDENTITY\n");
1470                 if (copy_to_user((void __user *)arg, blkdev->device_id,
1471                                  blkdev->device_id_len))
1472                         ret = -EFAULT;
1473                 break;
1474 #endif
1475         default:
1476                 ret = -EINVAL;
1477                 break;
1478         }
1479
1480         return ret;
1481 }
1482
1483 static int __init blkvsc_init(void)
1484 {
1485         int ret;
1486
1487         BUILD_BUG_ON(sizeof(sector_t) != 8);
1488
1489         DPRINT_INFO(BLKVSC_DRV, "Blkvsc initializing....");
1490
1491         ret = blkvsc_drv_init(blk_vsc_initialize);
1492
1493         return ret;
1494 }
1495
1496 static void __exit blkvsc_exit(void)
1497 {
1498         blkvsc_drv_exit();
1499 }
1500
1501 MODULE_LICENSE("GPL");
1502 MODULE_VERSION(HV_DRV_VERSION);
1503 MODULE_DESCRIPTION("Microsoft Hyper-V virtual block driver");
1504 module_init(blkvsc_init);
1505 module_exit(blkvsc_exit);