linux/drivers/scsi/sg.c
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   1/*
   2 *  History:
   3 *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4 *           to allow user process control of SCSI devices.
   5 *  Development Sponsored by Killy Corp. NY NY
   6 *
   7 * Original driver (sg.c):
   8 *        Copyright (C) 1992 Lawrence Foard
   9 * Version 2 and 3 extensions to driver:
  10 *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11 *
  12 *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2, or (at your option)
  17 * any later version.
  18 *
  19 */
  20
  21static int sg_version_num = 30534;      /* 2 digits for each component */
  22#define SG_VERSION_STR "3.5.34"
  23
  24/*
  25 *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26 *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27 *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28 *        (otherwise the macros compile to empty statements).
  29 *
  30 */
  31#include <linux/module.h>
  32
  33#include <linux/fs.h>
  34#include <linux/kernel.h>
  35#include <linux/sched.h>
  36#include <linux/string.h>
  37#include <linux/mm.h>
  38#include <linux/errno.h>
  39#include <linux/mtio.h>
  40#include <linux/ioctl.h>
  41#include <linux/slab.h>
  42#include <linux/fcntl.h>
  43#include <linux/init.h>
  44#include <linux/poll.h>
  45#include <linux/moduleparam.h>
  46#include <linux/cdev.h>
  47#include <linux/idr.h>
  48#include <linux/seq_file.h>
  49#include <linux/blkdev.h>
  50#include <linux/delay.h>
  51#include <linux/blktrace_api.h>
  52#include <linux/mutex.h>
  53#include <linux/ratelimit.h>
  54
  55#include "scsi.h"
  56#include <scsi/scsi_dbg.h>
  57#include <scsi/scsi_host.h>
  58#include <scsi/scsi_driver.h>
  59#include <scsi/scsi_ioctl.h>
  60#include <scsi/sg.h>
  61
  62#include "scsi_logging.h"
  63
  64#ifdef CONFIG_SCSI_PROC_FS
  65#include <linux/proc_fs.h>
  66static char *sg_version_date = "20061027";
  67
  68static int sg_proc_init(void);
  69static void sg_proc_cleanup(void);
  70#endif
  71
  72#define SG_ALLOW_DIO_DEF 0
  73
  74#define SG_MAX_DEVS 32768
  75
  76/*
  77 * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  78 * Then when using 32 bit integers x * m may overflow during the calculation.
  79 * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  80 * calculates the same, but prevents the overflow when both m and d
  81 * are "small" numbers (like HZ and USER_HZ).
  82 * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  83 * in 32 bits.
  84 */
  85#define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  86
  87#define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  88
  89int sg_big_buff = SG_DEF_RESERVED_SIZE;
  90/* N.B. This variable is readable and writeable via
  91   /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  92   of this size (or less if there is not enough memory) will be reserved
  93   for use by this file descriptor. [Deprecated usage: this variable is also
  94   readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  95   the kernel (i.e. it is not a module).] */
  96static int def_reserved_size = -1;      /* picks up init parameter */
  97static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  98
  99static int scatter_elem_sz = SG_SCATTER_SZ;
 100static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 101
 102#define SG_SECTOR_SZ 512
 103
 104static int sg_add(struct device *, struct class_interface *);
 105static void sg_remove(struct device *, struct class_interface *);
 106
 107static DEFINE_SPINLOCK(sg_open_exclusive_lock);
 108
 109static DEFINE_IDR(sg_index_idr);
 110static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 111                                                           file descriptor list for device */
 112
 113static struct class_interface sg_interface = {
 114        .add_dev        = sg_add,
 115        .remove_dev     = sg_remove,
 116};
 117
 118typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 119        unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 120        unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 121        unsigned bufflen;       /* Size of (aggregate) data buffer */
 122        struct page **pages;
 123        int page_order;
 124        char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 125        unsigned char cmd_opcode; /* first byte of command */
 126} Sg_scatter_hold;
 127
 128struct sg_device;               /* forward declarations */
 129struct sg_fd;
 130
 131typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 132        struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 133        struct sg_fd *parentfp; /* NULL -> not in use */
 134        Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 135        sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 136        unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 137        char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 138        char orphan;            /* 1 -> drop on sight, 0 -> normal */
 139        char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 140        /* done protected by rq_list_lock */
 141        char done;              /* 0->before bh, 1->before read, 2->read */
 142        struct request *rq;
 143        struct bio *bio;
 144        struct execute_work ew;
 145} Sg_request;
 146
 147typedef struct sg_fd {          /* holds the state of a file descriptor */
 148        /* sfd_siblings is protected by sg_index_lock */
 149        struct list_head sfd_siblings;
 150        struct sg_device *parentdp;     /* owning device */
 151        wait_queue_head_t read_wait;    /* queue read until command done */
 152        rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 153        int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 154        int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 155        Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 156        unsigned save_scat_len; /* original length of trunc. scat. element */
 157        Sg_request *headrp;     /* head of request slist, NULL->empty */
 158        struct fasync_struct *async_qp; /* used by asynchronous notification */
 159        Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 160        char low_dma;           /* as in parent but possibly overridden to 1 */
 161        char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 162        char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 163        char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 164        char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 165        char mmap_called;       /* 0 -> mmap() never called on this fd */
 166        struct kref f_ref;
 167        struct execute_work ew;
 168} Sg_fd;
 169
 170typedef struct sg_device { /* holds the state of each scsi generic device */
 171        struct scsi_device *device;
 172        wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 173        int sg_tablesize;       /* adapter's max scatter-gather table size */
 174        u32 index;              /* device index number */
 175        /* sfds is protected by sg_index_lock */
 176        struct list_head sfds;
 177        volatile char detached; /* 0->attached, 1->detached pending removal */
 178        /* exclude protected by sg_open_exclusive_lock */
 179        char exclude;           /* opened for exclusive access */
 180        char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 181        struct gendisk *disk;
 182        struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 183        struct kref d_ref;
 184} Sg_device;
 185
 186/* tasklet or soft irq callback */
 187static void sg_rq_end_io(struct request *rq, int uptodate);
 188static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 189static int sg_finish_rem_req(Sg_request * srp);
 190static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 191static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 192                           Sg_request * srp);
 193static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 194                        const char __user *buf, size_t count, int blocking,
 195                        int read_only, int sg_io_owned, Sg_request **o_srp);
 196static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 197                           unsigned char *cmnd, int timeout, int blocking);
 198static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 199static void sg_remove_scat(Sg_scatter_hold * schp);
 200static void sg_build_reserve(Sg_fd * sfp, int req_size);
 201static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 202static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 203static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 204static void sg_remove_sfp(struct kref *);
 205static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 206static Sg_request *sg_add_request(Sg_fd * sfp);
 207static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 208static int sg_res_in_use(Sg_fd * sfp);
 209static Sg_device *sg_get_dev(int dev);
 210static void sg_put_dev(Sg_device *sdp);
 211
 212#define SZ_SG_HEADER sizeof(struct sg_header)
 213#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 214#define SZ_SG_IOVEC sizeof(sg_iovec_t)
 215#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 216
 217static int sg_allow_access(struct file *filp, unsigned char *cmd)
 218{
 219        struct sg_fd *sfp = filp->private_data;
 220
 221        if (sfp->parentdp->device->type == TYPE_SCANNER)
 222                return 0;
 223
 224        return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 225}
 226
 227static int get_exclude(Sg_device *sdp)
 228{
 229        unsigned long flags;
 230        int ret;
 231
 232        spin_lock_irqsave(&sg_open_exclusive_lock, flags);
 233        ret = sdp->exclude;
 234        spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
 235        return ret;
 236}
 237
 238static int set_exclude(Sg_device *sdp, char val)
 239{
 240        unsigned long flags;
 241
 242        spin_lock_irqsave(&sg_open_exclusive_lock, flags);
 243        sdp->exclude = val;
 244        spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
 245        return val;
 246}
 247
 248static int sfds_list_empty(Sg_device *sdp)
 249{
 250        unsigned long flags;
 251        int ret;
 252
 253        read_lock_irqsave(&sg_index_lock, flags);
 254        ret = list_empty(&sdp->sfds);
 255        read_unlock_irqrestore(&sg_index_lock, flags);
 256        return ret;
 257}
 258
 259static int
 260sg_open(struct inode *inode, struct file *filp)
 261{
 262        int dev = iminor(inode);
 263        int flags = filp->f_flags;
 264        struct request_queue *q;
 265        Sg_device *sdp;
 266        Sg_fd *sfp;
 267        int res;
 268        int retval;
 269
 270        nonseekable_open(inode, filp);
 271        SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 272        sdp = sg_get_dev(dev);
 273        if (IS_ERR(sdp)) {
 274                retval = PTR_ERR(sdp);
 275                sdp = NULL;
 276                goto sg_put;
 277        }
 278
 279        /* This driver's module count bumped by fops_get in <linux/fs.h> */
 280        /* Prevent the device driver from vanishing while we sleep */
 281        retval = scsi_device_get(sdp->device);
 282        if (retval)
 283                goto sg_put;
 284
 285        retval = scsi_autopm_get_device(sdp->device);
 286        if (retval)
 287                goto sdp_put;
 288
 289        if (!((flags & O_NONBLOCK) ||
 290              scsi_block_when_processing_errors(sdp->device))) {
 291                retval = -ENXIO;
 292                /* we are in error recovery for this device */
 293                goto error_out;
 294        }
 295
 296        if (flags & O_EXCL) {
 297                if (O_RDONLY == (flags & O_ACCMODE)) {
 298                        retval = -EPERM; /* Can't lock it with read only access */
 299                        goto error_out;
 300                }
 301                if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
 302                        retval = -EBUSY;
 303                        goto error_out;
 304                }
 305                res = wait_event_interruptible(sdp->o_excl_wait,
 306                                           ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
 307                if (res) {
 308                        retval = res;   /* -ERESTARTSYS because signal hit process */
 309                        goto error_out;
 310                }
 311        } else if (get_exclude(sdp)) {  /* some other fd has an exclusive lock on dev */
 312                if (flags & O_NONBLOCK) {
 313                        retval = -EBUSY;
 314                        goto error_out;
 315                }
 316                res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
 317                if (res) {
 318                        retval = res;   /* -ERESTARTSYS because signal hit process */
 319                        goto error_out;
 320                }
 321        }
 322        if (sdp->detached) {
 323                retval = -ENODEV;
 324                goto error_out;
 325        }
 326        if (sfds_list_empty(sdp)) {     /* no existing opens on this device */
 327                sdp->sgdebug = 0;
 328                q = sdp->device->request_queue;
 329                sdp->sg_tablesize = queue_max_segments(q);
 330        }
 331        if ((sfp = sg_add_sfp(sdp, dev)))
 332                filp->private_data = sfp;
 333        else {
 334                if (flags & O_EXCL) {
 335                        set_exclude(sdp, 0);    /* undo if error */
 336                        wake_up_interruptible(&sdp->o_excl_wait);
 337                }
 338                retval = -ENOMEM;
 339                goto error_out;
 340        }
 341        retval = 0;
 342error_out:
 343        if (retval) {
 344                scsi_autopm_put_device(sdp->device);
 345sdp_put:
 346                scsi_device_put(sdp->device);
 347        }
 348sg_put:
 349        if (sdp)
 350                sg_put_dev(sdp);
 351        return retval;
 352}
 353
 354/* Following function was formerly called 'sg_close' */
 355static int
 356sg_release(struct inode *inode, struct file *filp)
 357{
 358        Sg_device *sdp;
 359        Sg_fd *sfp;
 360
 361        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 362                return -ENXIO;
 363        SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 364
 365        set_exclude(sdp, 0);
 366        wake_up_interruptible(&sdp->o_excl_wait);
 367
 368        scsi_autopm_put_device(sdp->device);
 369        kref_put(&sfp->f_ref, sg_remove_sfp);
 370        return 0;
 371}
 372
 373static ssize_t
 374sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 375{
 376        Sg_device *sdp;
 377        Sg_fd *sfp;
 378        Sg_request *srp;
 379        int req_pack_id = -1;
 380        sg_io_hdr_t *hp;
 381        struct sg_header *old_hdr = NULL;
 382        int retval = 0;
 383
 384        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 385                return -ENXIO;
 386        SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 387                                   sdp->disk->disk_name, (int) count));
 388
 389        if (!access_ok(VERIFY_WRITE, buf, count))
 390                return -EFAULT;
 391        if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 392                old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 393                if (!old_hdr)
 394                        return -ENOMEM;
 395                if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 396                        retval = -EFAULT;
 397                        goto free_old_hdr;
 398                }
 399                if (old_hdr->reply_len < 0) {
 400                        if (count >= SZ_SG_IO_HDR) {
 401                                sg_io_hdr_t *new_hdr;
 402                                new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 403                                if (!new_hdr) {
 404                                        retval = -ENOMEM;
 405                                        goto free_old_hdr;
 406                                }
 407                                retval =__copy_from_user
 408                                    (new_hdr, buf, SZ_SG_IO_HDR);
 409                                req_pack_id = new_hdr->pack_id;
 410                                kfree(new_hdr);
 411                                if (retval) {
 412                                        retval = -EFAULT;
 413                                        goto free_old_hdr;
 414                                }
 415                        }
 416                } else
 417                        req_pack_id = old_hdr->pack_id;
 418        }
 419        srp = sg_get_rq_mark(sfp, req_pack_id);
 420        if (!srp) {             /* now wait on packet to arrive */
 421                if (sdp->detached) {
 422                        retval = -ENODEV;
 423                        goto free_old_hdr;
 424                }
 425                if (filp->f_flags & O_NONBLOCK) {
 426                        retval = -EAGAIN;
 427                        goto free_old_hdr;
 428                }
 429                retval = wait_event_interruptible(sfp->read_wait,
 430                        (sdp->detached ||
 431                        (srp = sg_get_rq_mark(sfp, req_pack_id))));
 432                if (sdp->detached) {
 433                        retval = -ENODEV;
 434                        goto free_old_hdr;
 435                }
 436                if (retval) {
 437                        /* -ERESTARTSYS as signal hit process */
 438                        goto free_old_hdr;
 439                }
 440        }
 441        if (srp->header.interface_id != '\0') {
 442                retval = sg_new_read(sfp, buf, count, srp);
 443                goto free_old_hdr;
 444        }
 445
 446        hp = &srp->header;
 447        if (old_hdr == NULL) {
 448                old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 449                if (! old_hdr) {
 450                        retval = -ENOMEM;
 451                        goto free_old_hdr;
 452                }
 453        }
 454        memset(old_hdr, 0, SZ_SG_HEADER);
 455        old_hdr->reply_len = (int) hp->timeout;
 456        old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 457        old_hdr->pack_id = hp->pack_id;
 458        old_hdr->twelve_byte =
 459            ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 460        old_hdr->target_status = hp->masked_status;
 461        old_hdr->host_status = hp->host_status;
 462        old_hdr->driver_status = hp->driver_status;
 463        if ((CHECK_CONDITION & hp->masked_status) ||
 464            (DRIVER_SENSE & hp->driver_status))
 465                memcpy(old_hdr->sense_buffer, srp->sense_b,
 466                       sizeof (old_hdr->sense_buffer));
 467        switch (hp->host_status) {
 468        /* This setup of 'result' is for backward compatibility and is best
 469           ignored by the user who should use target, host + driver status */
 470        case DID_OK:
 471        case DID_PASSTHROUGH:
 472        case DID_SOFT_ERROR:
 473                old_hdr->result = 0;
 474                break;
 475        case DID_NO_CONNECT:
 476        case DID_BUS_BUSY:
 477        case DID_TIME_OUT:
 478                old_hdr->result = EBUSY;
 479                break;
 480        case DID_BAD_TARGET:
 481        case DID_ABORT:
 482        case DID_PARITY:
 483        case DID_RESET:
 484        case DID_BAD_INTR:
 485                old_hdr->result = EIO;
 486                break;
 487        case DID_ERROR:
 488                old_hdr->result = (srp->sense_b[0] == 0 && 
 489                                  hp->masked_status == GOOD) ? 0 : EIO;
 490                break;
 491        default:
 492                old_hdr->result = EIO;
 493                break;
 494        }
 495
 496        /* Now copy the result back to the user buffer.  */
 497        if (count >= SZ_SG_HEADER) {
 498                if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 499                        retval = -EFAULT;
 500                        goto free_old_hdr;
 501                }
 502                buf += SZ_SG_HEADER;
 503                if (count > old_hdr->reply_len)
 504                        count = old_hdr->reply_len;
 505                if (count > SZ_SG_HEADER) {
 506                        if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 507                                retval = -EFAULT;
 508                                goto free_old_hdr;
 509                        }
 510                }
 511        } else
 512                count = (old_hdr->result == 0) ? 0 : -EIO;
 513        sg_finish_rem_req(srp);
 514        retval = count;
 515free_old_hdr:
 516        kfree(old_hdr);
 517        return retval;
 518}
 519
 520static ssize_t
 521sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 522{
 523        sg_io_hdr_t *hp = &srp->header;
 524        int err = 0;
 525        int len;
 526
 527        if (count < SZ_SG_IO_HDR) {
 528                err = -EINVAL;
 529                goto err_out;
 530        }
 531        hp->sb_len_wr = 0;
 532        if ((hp->mx_sb_len > 0) && hp->sbp) {
 533                if ((CHECK_CONDITION & hp->masked_status) ||
 534                    (DRIVER_SENSE & hp->driver_status)) {
 535                        int sb_len = SCSI_SENSE_BUFFERSIZE;
 536                        sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 537                        len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 538                        len = (len > sb_len) ? sb_len : len;
 539                        if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 540                                err = -EFAULT;
 541                                goto err_out;
 542                        }
 543                        hp->sb_len_wr = len;
 544                }
 545        }
 546        if (hp->masked_status || hp->host_status || hp->driver_status)
 547                hp->info |= SG_INFO_CHECK;
 548        if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 549                err = -EFAULT;
 550                goto err_out;
 551        }
 552err_out:
 553        err = sg_finish_rem_req(srp);
 554        return (0 == err) ? count : err;
 555}
 556
 557static ssize_t
 558sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 559{
 560        int mxsize, cmd_size, k;
 561        int input_size, blocking;
 562        unsigned char opcode;
 563        Sg_device *sdp;
 564        Sg_fd *sfp;
 565        Sg_request *srp;
 566        struct sg_header old_hdr;
 567        sg_io_hdr_t *hp;
 568        unsigned char cmnd[MAX_COMMAND_SIZE];
 569
 570        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 571                return -ENXIO;
 572        SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 573                                   sdp->disk->disk_name, (int) count));
 574        if (sdp->detached)
 575                return -ENODEV;
 576        if (!((filp->f_flags & O_NONBLOCK) ||
 577              scsi_block_when_processing_errors(sdp->device)))
 578                return -ENXIO;
 579
 580        if (!access_ok(VERIFY_READ, buf, count))
 581                return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 582        if (count < SZ_SG_HEADER)
 583                return -EIO;
 584        if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 585                return -EFAULT;
 586        blocking = !(filp->f_flags & O_NONBLOCK);
 587        if (old_hdr.reply_len < 0)
 588                return sg_new_write(sfp, filp, buf, count,
 589                                    blocking, 0, 0, NULL);
 590        if (count < (SZ_SG_HEADER + 6))
 591                return -EIO;    /* The minimum scsi command length is 6 bytes. */
 592
 593        if (!(srp = sg_add_request(sfp))) {
 594                SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 595                return -EDOM;
 596        }
 597        buf += SZ_SG_HEADER;
 598        __get_user(opcode, buf);
 599        if (sfp->next_cmd_len > 0) {
 600                if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 601                        SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 602                        sfp->next_cmd_len = 0;
 603                        sg_remove_request(sfp, srp);
 604                        return -EIO;
 605                }
 606                cmd_size = sfp->next_cmd_len;
 607                sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 608        } else {
 609                cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 610                if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 611                        cmd_size = 12;
 612        }
 613        SCSI_LOG_TIMEOUT(4, printk(
 614                "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 615/* Determine buffer size.  */
 616        input_size = count - cmd_size;
 617        mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 618        mxsize -= SZ_SG_HEADER;
 619        input_size -= SZ_SG_HEADER;
 620        if (input_size < 0) {
 621                sg_remove_request(sfp, srp);
 622                return -EIO;    /* User did not pass enough bytes for this command. */
 623        }
 624        hp = &srp->header;
 625        hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 626        hp->cmd_len = (unsigned char) cmd_size;
 627        hp->iovec_count = 0;
 628        hp->mx_sb_len = 0;
 629        if (input_size > 0)
 630                hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 631                    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 632        else
 633                hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 634        hp->dxfer_len = mxsize;
 635        if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 636                hp->dxferp = (char __user *)buf + cmd_size;
 637        else
 638                hp->dxferp = NULL;
 639        hp->sbp = NULL;
 640        hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 641        hp->flags = input_size; /* structure abuse ... */
 642        hp->pack_id = old_hdr.pack_id;
 643        hp->usr_ptr = NULL;
 644        if (__copy_from_user(cmnd, buf, cmd_size))
 645                return -EFAULT;
 646        /*
 647         * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 648         * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 649         * is a non-zero input_size, so emit a warning.
 650         */
 651        if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 652                static char cmd[TASK_COMM_LEN];
 653                if (strcmp(current->comm, cmd)) {
 654                        printk_ratelimited(KERN_WARNING
 655                                           "sg_write: data in/out %d/%d bytes "
 656                                           "for SCSI command 0x%x-- guessing "
 657                                           "data in;\n   program %s not setting "
 658                                           "count and/or reply_len properly\n",
 659                                           old_hdr.reply_len - (int)SZ_SG_HEADER,
 660                                           input_size, (unsigned int) cmnd[0],
 661                                           current->comm);
 662                        strcpy(cmd, current->comm);
 663                }
 664        }
 665        k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 666        return (k < 0) ? k : count;
 667}
 668
 669static ssize_t
 670sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 671                 size_t count, int blocking, int read_only, int sg_io_owned,
 672                 Sg_request **o_srp)
 673{
 674        int k;
 675        Sg_request *srp;
 676        sg_io_hdr_t *hp;
 677        unsigned char cmnd[MAX_COMMAND_SIZE];
 678        int timeout;
 679        unsigned long ul_timeout;
 680
 681        if (count < SZ_SG_IO_HDR)
 682                return -EINVAL;
 683        if (!access_ok(VERIFY_READ, buf, count))
 684                return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 685
 686        sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 687        if (!(srp = sg_add_request(sfp))) {
 688                SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 689                return -EDOM;
 690        }
 691        srp->sg_io_owned = sg_io_owned;
 692        hp = &srp->header;
 693        if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 694                sg_remove_request(sfp, srp);
 695                return -EFAULT;
 696        }
 697        if (hp->interface_id != 'S') {
 698                sg_remove_request(sfp, srp);
 699                return -ENOSYS;
 700        }
 701        if (hp->flags & SG_FLAG_MMAP_IO) {
 702                if (hp->dxfer_len > sfp->reserve.bufflen) {
 703                        sg_remove_request(sfp, srp);
 704                        return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 705                }
 706                if (hp->flags & SG_FLAG_DIRECT_IO) {
 707                        sg_remove_request(sfp, srp);
 708                        return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 709                }
 710                if (sg_res_in_use(sfp)) {
 711                        sg_remove_request(sfp, srp);
 712                        return -EBUSY;  /* reserve buffer already being used */
 713                }
 714        }
 715        ul_timeout = msecs_to_jiffies(srp->header.timeout);
 716        timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 717        if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 718                sg_remove_request(sfp, srp);
 719                return -EMSGSIZE;
 720        }
 721        if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 722                sg_remove_request(sfp, srp);
 723                return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 724        }
 725        if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 726                sg_remove_request(sfp, srp);
 727                return -EFAULT;
 728        }
 729        if (read_only && sg_allow_access(file, cmnd)) {
 730                sg_remove_request(sfp, srp);
 731                return -EPERM;
 732        }
 733        k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 734        if (k < 0)
 735                return k;
 736        if (o_srp)
 737                *o_srp = srp;
 738        return count;
 739}
 740
 741static int
 742sg_common_write(Sg_fd * sfp, Sg_request * srp,
 743                unsigned char *cmnd, int timeout, int blocking)
 744{
 745        int k, data_dir;
 746        Sg_device *sdp = sfp->parentdp;
 747        sg_io_hdr_t *hp = &srp->header;
 748
 749        srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 750        hp->status = 0;
 751        hp->masked_status = 0;
 752        hp->msg_status = 0;
 753        hp->info = 0;
 754        hp->host_status = 0;
 755        hp->driver_status = 0;
 756        hp->resid = 0;
 757        SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 758                          (int) cmnd[0], (int) hp->cmd_len));
 759
 760        k = sg_start_req(srp, cmnd);
 761        if (k) {
 762                SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 763                sg_finish_rem_req(srp);
 764                return k;       /* probably out of space --> ENOMEM */
 765        }
 766        if (sdp->detached) {
 767                if (srp->bio)
 768                        blk_end_request_all(srp->rq, -EIO);
 769                sg_finish_rem_req(srp);
 770                return -ENODEV;
 771        }
 772
 773        switch (hp->dxfer_direction) {
 774        case SG_DXFER_TO_FROM_DEV:
 775        case SG_DXFER_FROM_DEV:
 776                data_dir = DMA_FROM_DEVICE;
 777                break;
 778        case SG_DXFER_TO_DEV:
 779                data_dir = DMA_TO_DEVICE;
 780                break;
 781        case SG_DXFER_UNKNOWN:
 782                data_dir = DMA_BIDIRECTIONAL;
 783                break;
 784        default:
 785                data_dir = DMA_NONE;
 786                break;
 787        }
 788        hp->duration = jiffies_to_msecs(jiffies);
 789
 790        srp->rq->timeout = timeout;
 791        kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 792        blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 793                              srp->rq, 1, sg_rq_end_io);
 794        return 0;
 795}
 796
 797static int srp_done(Sg_fd *sfp, Sg_request *srp)
 798{
 799        unsigned long flags;
 800        int ret;
 801
 802        read_lock_irqsave(&sfp->rq_list_lock, flags);
 803        ret = srp->done;
 804        read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 805        return ret;
 806}
 807
 808static long
 809sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 810{
 811        void __user *p = (void __user *)arg;
 812        int __user *ip = p;
 813        int result, val, read_only;
 814        Sg_device *sdp;
 815        Sg_fd *sfp;
 816        Sg_request *srp;
 817        unsigned long iflags;
 818
 819        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 820                return -ENXIO;
 821
 822        SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 823                                   sdp->disk->disk_name, (int) cmd_in));
 824        read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 825
 826        switch (cmd_in) {
 827        case SG_IO:
 828                if (sdp->detached)
 829                        return -ENODEV;
 830                if (!scsi_block_when_processing_errors(sdp->device))
 831                        return -ENXIO;
 832                if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 833                        return -EFAULT;
 834                result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 835                                 1, read_only, 1, &srp);
 836                if (result < 0)
 837                        return result;
 838                result = wait_event_interruptible(sfp->read_wait,
 839                        (srp_done(sfp, srp) || sdp->detached));
 840                if (sdp->detached)
 841                        return -ENODEV;
 842                write_lock_irq(&sfp->rq_list_lock);
 843                if (srp->done) {
 844                        srp->done = 2;
 845                        write_unlock_irq(&sfp->rq_list_lock);
 846                        result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 847                        return (result < 0) ? result : 0;
 848                }
 849                srp->orphan = 1;
 850                write_unlock_irq(&sfp->rq_list_lock);
 851                return result;  /* -ERESTARTSYS because signal hit process */
 852        case SG_SET_TIMEOUT:
 853                result = get_user(val, ip);
 854                if (result)
 855                        return result;
 856                if (val < 0)
 857                        return -EIO;
 858                if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 859                    val = MULDIV (INT_MAX, USER_HZ, HZ);
 860                sfp->timeout_user = val;
 861                sfp->timeout = MULDIV (val, HZ, USER_HZ);
 862
 863                return 0;
 864        case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 865                                /* strange ..., for backward compatibility */
 866                return sfp->timeout_user;
 867        case SG_SET_FORCE_LOW_DMA:
 868                result = get_user(val, ip);
 869                if (result)
 870                        return result;
 871                if (val) {
 872                        sfp->low_dma = 1;
 873                        if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 874                                val = (int) sfp->reserve.bufflen;
 875                                sg_remove_scat(&sfp->reserve);
 876                                sg_build_reserve(sfp, val);
 877                        }
 878                } else {
 879                        if (sdp->detached)
 880                                return -ENODEV;
 881                        sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 882                }
 883                return 0;
 884        case SG_GET_LOW_DMA:
 885                return put_user((int) sfp->low_dma, ip);
 886        case SG_GET_SCSI_ID:
 887                if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 888                        return -EFAULT;
 889                else {
 890                        sg_scsi_id_t __user *sg_idp = p;
 891
 892                        if (sdp->detached)
 893                                return -ENODEV;
 894                        __put_user((int) sdp->device->host->host_no,
 895                                   &sg_idp->host_no);
 896                        __put_user((int) sdp->device->channel,
 897                                   &sg_idp->channel);
 898                        __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 899                        __put_user((int) sdp->device->lun, &sg_idp->lun);
 900                        __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 901                        __put_user((short) sdp->device->host->cmd_per_lun,
 902                                   &sg_idp->h_cmd_per_lun);
 903                        __put_user((short) sdp->device->queue_depth,
 904                                   &sg_idp->d_queue_depth);
 905                        __put_user(0, &sg_idp->unused[0]);
 906                        __put_user(0, &sg_idp->unused[1]);
 907                        return 0;
 908                }
 909        case SG_SET_FORCE_PACK_ID:
 910                result = get_user(val, ip);
 911                if (result)
 912                        return result;
 913                sfp->force_packid = val ? 1 : 0;
 914                return 0;
 915        case SG_GET_PACK_ID:
 916                if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 917                        return -EFAULT;
 918                read_lock_irqsave(&sfp->rq_list_lock, iflags);
 919                for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 920                        if ((1 == srp->done) && (!srp->sg_io_owned)) {
 921                                read_unlock_irqrestore(&sfp->rq_list_lock,
 922                                                       iflags);
 923                                __put_user(srp->header.pack_id, ip);
 924                                return 0;
 925                        }
 926                }
 927                read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 928                __put_user(-1, ip);
 929                return 0;
 930        case SG_GET_NUM_WAITING:
 931                read_lock_irqsave(&sfp->rq_list_lock, iflags);
 932                for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 933                        if ((1 == srp->done) && (!srp->sg_io_owned))
 934                                ++val;
 935                }
 936                read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 937                return put_user(val, ip);
 938        case SG_GET_SG_TABLESIZE:
 939                return put_user(sdp->sg_tablesize, ip);
 940        case SG_SET_RESERVED_SIZE:
 941                result = get_user(val, ip);
 942                if (result)
 943                        return result;
 944                if (val < 0)
 945                        return -EINVAL;
 946                val = min_t(int, val,
 947                            queue_max_sectors(sdp->device->request_queue) * 512);
 948                if (val != sfp->reserve.bufflen) {
 949                        if (sg_res_in_use(sfp) || sfp->mmap_called)
 950                                return -EBUSY;
 951                        sg_remove_scat(&sfp->reserve);
 952                        sg_build_reserve(sfp, val);
 953                }
 954                return 0;
 955        case SG_GET_RESERVED_SIZE:
 956                val = min_t(int, sfp->reserve.bufflen,
 957                            queue_max_sectors(sdp->device->request_queue) * 512);
 958                return put_user(val, ip);
 959        case SG_SET_COMMAND_Q:
 960                result = get_user(val, ip);
 961                if (result)
 962                        return result;
 963                sfp->cmd_q = val ? 1 : 0;
 964                return 0;
 965        case SG_GET_COMMAND_Q:
 966                return put_user((int) sfp->cmd_q, ip);
 967        case SG_SET_KEEP_ORPHAN:
 968                result = get_user(val, ip);
 969                if (result)
 970                        return result;
 971                sfp->keep_orphan = val;
 972                return 0;
 973        case SG_GET_KEEP_ORPHAN:
 974                return put_user((int) sfp->keep_orphan, ip);
 975        case SG_NEXT_CMD_LEN:
 976                result = get_user(val, ip);
 977                if (result)
 978                        return result;
 979                sfp->next_cmd_len = (val > 0) ? val : 0;
 980                return 0;
 981        case SG_GET_VERSION_NUM:
 982                return put_user(sg_version_num, ip);
 983        case SG_GET_ACCESS_COUNT:
 984                /* faked - we don't have a real access count anymore */
 985                val = (sdp->device ? 1 : 0);
 986                return put_user(val, ip);
 987        case SG_GET_REQUEST_TABLE:
 988                if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 989                        return -EFAULT;
 990                else {
 991                        sg_req_info_t *rinfo;
 992                        unsigned int ms;
 993
 994                        rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 995                                                                GFP_KERNEL);
 996                        if (!rinfo)
 997                                return -ENOMEM;
 998                        read_lock_irqsave(&sfp->rq_list_lock, iflags);
 999                        for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1000                             ++val, srp = srp ? srp->nextrp : srp) {
1001                                memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1002                                if (srp) {
1003                                        rinfo[val].req_state = srp->done + 1;
1004                                        rinfo[val].problem =
1005                                            srp->header.masked_status & 
1006                                            srp->header.host_status & 
1007                                            srp->header.driver_status;
1008                                        if (srp->done)
1009                                                rinfo[val].duration =
1010                                                        srp->header.duration;
1011                                        else {
1012                                                ms = jiffies_to_msecs(jiffies);
1013                                                rinfo[val].duration =
1014                                                    (ms > srp->header.duration) ?
1015                                                    (ms - srp->header.duration) : 0;
1016                                        }
1017                                        rinfo[val].orphan = srp->orphan;
1018                                        rinfo[val].sg_io_owned =
1019                                                        srp->sg_io_owned;
1020                                        rinfo[val].pack_id =
1021                                                        srp->header.pack_id;
1022                                        rinfo[val].usr_ptr =
1023                                                        srp->header.usr_ptr;
1024                                }
1025                        }
1026                        read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1027                        result = __copy_to_user(p, rinfo, 
1028                                                SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1029                        result = result ? -EFAULT : 0;
1030                        kfree(rinfo);
1031                        return result;
1032                }
1033        case SG_EMULATED_HOST:
1034                if (sdp->detached)
1035                        return -ENODEV;
1036                return put_user(sdp->device->host->hostt->emulated, ip);
1037        case SG_SCSI_RESET:
1038                if (sdp->detached)
1039                        return -ENODEV;
1040                if (filp->f_flags & O_NONBLOCK) {
1041                        if (scsi_host_in_recovery(sdp->device->host))
1042                                return -EBUSY;
1043                } else if (!scsi_block_when_processing_errors(sdp->device))
1044                        return -EBUSY;
1045                result = get_user(val, ip);
1046                if (result)
1047                        return result;
1048                if (SG_SCSI_RESET_NOTHING == val)
1049                        return 0;
1050                switch (val) {
1051                case SG_SCSI_RESET_DEVICE:
1052                        val = SCSI_TRY_RESET_DEVICE;
1053                        break;
1054                case SG_SCSI_RESET_TARGET:
1055                        val = SCSI_TRY_RESET_TARGET;
1056                        break;
1057                case SG_SCSI_RESET_BUS:
1058                        val = SCSI_TRY_RESET_BUS;
1059                        break;
1060                case SG_SCSI_RESET_HOST:
1061                        val = SCSI_TRY_RESET_HOST;
1062                        break;
1063                default:
1064                        return -EINVAL;
1065                }
1066                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1067                        return -EACCES;
1068                return (scsi_reset_provider(sdp->device, val) ==
1069                        SUCCESS) ? 0 : -EIO;
1070        case SCSI_IOCTL_SEND_COMMAND:
1071                if (sdp->detached)
1072                        return -ENODEV;
1073                if (read_only) {
1074                        unsigned char opcode = WRITE_6;
1075                        Scsi_Ioctl_Command __user *siocp = p;
1076
1077                        if (copy_from_user(&opcode, siocp->data, 1))
1078                                return -EFAULT;
1079                        if (sg_allow_access(filp, &opcode))
1080                                return -EPERM;
1081                }
1082                return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1083        case SG_SET_DEBUG:
1084                result = get_user(val, ip);
1085                if (result)
1086                        return result;
1087                sdp->sgdebug = (char) val;
1088                return 0;
1089        case SCSI_IOCTL_GET_IDLUN:
1090        case SCSI_IOCTL_GET_BUS_NUMBER:
1091        case SCSI_IOCTL_PROBE_HOST:
1092        case SG_GET_TRANSFORM:
1093                if (sdp->detached)
1094                        return -ENODEV;
1095                return scsi_ioctl(sdp->device, cmd_in, p);
1096        case BLKSECTGET:
1097                return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1098                                ip);
1099        case BLKTRACESETUP:
1100                return blk_trace_setup(sdp->device->request_queue,
1101                                       sdp->disk->disk_name,
1102                                       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1103                                       NULL,
1104                                       (char *)arg);
1105        case BLKTRACESTART:
1106                return blk_trace_startstop(sdp->device->request_queue, 1);
1107        case BLKTRACESTOP:
1108                return blk_trace_startstop(sdp->device->request_queue, 0);
1109        case BLKTRACETEARDOWN:
1110                return blk_trace_remove(sdp->device->request_queue);
1111        default:
1112                if (read_only)
1113                        return -EPERM;  /* don't know so take safe approach */
1114                return scsi_ioctl(sdp->device, cmd_in, p);
1115        }
1116}
1117
1118#ifdef CONFIG_COMPAT
1119static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1120{
1121        Sg_device *sdp;
1122        Sg_fd *sfp;
1123        struct scsi_device *sdev;
1124
1125        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1126                return -ENXIO;
1127
1128        sdev = sdp->device;
1129        if (sdev->host->hostt->compat_ioctl) { 
1130                int ret;
1131
1132                ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1133
1134                return ret;
1135        }
1136        
1137        return -ENOIOCTLCMD;
1138}
1139#endif
1140
1141static unsigned int
1142sg_poll(struct file *filp, poll_table * wait)
1143{
1144        unsigned int res = 0;
1145        Sg_device *sdp;
1146        Sg_fd *sfp;
1147        Sg_request *srp;
1148        int count = 0;
1149        unsigned long iflags;
1150
1151        sfp = filp->private_data;
1152        if (!sfp)
1153                return POLLERR;
1154        sdp = sfp->parentdp;
1155        if (!sdp)
1156                return POLLERR;
1157        poll_wait(filp, &sfp->read_wait, wait);
1158        read_lock_irqsave(&sfp->rq_list_lock, iflags);
1159        for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1160                /* if any read waiting, flag it */
1161                if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1162                        res = POLLIN | POLLRDNORM;
1163                ++count;
1164        }
1165        read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1166
1167        if (sdp->detached)
1168                res |= POLLHUP;
1169        else if (!sfp->cmd_q) {
1170                if (0 == count)
1171                        res |= POLLOUT | POLLWRNORM;
1172        } else if (count < SG_MAX_QUEUE)
1173                res |= POLLOUT | POLLWRNORM;
1174        SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1175                                   sdp->disk->disk_name, (int) res));
1176        return res;
1177}
1178
1179static int
1180sg_fasync(int fd, struct file *filp, int mode)
1181{
1182        Sg_device *sdp;
1183        Sg_fd *sfp;
1184
1185        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1186                return -ENXIO;
1187        SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1188                                   sdp->disk->disk_name, mode));
1189
1190        return fasync_helper(fd, filp, mode, &sfp->async_qp);
1191}
1192
1193static int
1194sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1195{
1196        Sg_fd *sfp;
1197        unsigned long offset, len, sa;
1198        Sg_scatter_hold *rsv_schp;
1199        int k, length;
1200
1201        if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1202                return VM_FAULT_SIGBUS;
1203        rsv_schp = &sfp->reserve;
1204        offset = vmf->pgoff << PAGE_SHIFT;
1205        if (offset >= rsv_schp->bufflen)
1206                return VM_FAULT_SIGBUS;
1207        SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1208                                   offset, rsv_schp->k_use_sg));
1209        sa = vma->vm_start;
1210        length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1211        for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1212                len = vma->vm_end - sa;
1213                len = (len < length) ? len : length;
1214                if (offset < len) {
1215                        struct page *page = nth_page(rsv_schp->pages[k],
1216                                                     offset >> PAGE_SHIFT);
1217                        get_page(page); /* increment page count */
1218                        vmf->page = page;
1219                        return 0; /* success */
1220                }
1221                sa += len;
1222                offset -= len;
1223        }
1224
1225        return VM_FAULT_SIGBUS;
1226}
1227
1228static const struct vm_operations_struct sg_mmap_vm_ops = {
1229        .fault = sg_vma_fault,
1230};
1231
1232static int
1233sg_mmap(struct file *filp, struct vm_area_struct *vma)
1234{
1235        Sg_fd *sfp;
1236        unsigned long req_sz, len, sa;
1237        Sg_scatter_hold *rsv_schp;
1238        int k, length;
1239
1240        if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1241                return -ENXIO;
1242        req_sz = vma->vm_end - vma->vm_start;
1243        SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1244                                   (void *) vma->vm_start, (int) req_sz));
1245        if (vma->vm_pgoff)
1246                return -EINVAL; /* want no offset */
1247        rsv_schp = &sfp->reserve;
1248        if (req_sz > rsv_schp->bufflen)
1249                return -ENOMEM; /* cannot map more than reserved buffer */
1250
1251        sa = vma->vm_start;
1252        length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1253        for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1254                len = vma->vm_end - sa;
1255                len = (len < length) ? len : length;
1256                sa += len;
1257        }
1258
1259        sfp->mmap_called = 1;
1260        vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1261        vma->vm_private_data = sfp;
1262        vma->vm_ops = &sg_mmap_vm_ops;
1263        return 0;
1264}
1265
1266static void sg_rq_end_io_usercontext(struct work_struct *work)
1267{
1268        struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1269        struct sg_fd *sfp = srp->parentfp;
1270
1271        sg_finish_rem_req(srp);
1272        kref_put(&sfp->f_ref, sg_remove_sfp);
1273}
1274
1275/*
1276 * This function is a "bottom half" handler that is called by the mid
1277 * level when a command is completed (or has failed).
1278 */
1279static void sg_rq_end_io(struct request *rq, int uptodate)
1280{
1281        struct sg_request *srp = rq->end_io_data;
1282        Sg_device *sdp;
1283        Sg_fd *sfp;
1284        unsigned long iflags;
1285        unsigned int ms;
1286        char *sense;
1287        int result, resid, done = 1;
1288
1289        if (WARN_ON(srp->done != 0))
1290                return;
1291
1292        sfp = srp->parentfp;
1293        if (WARN_ON(sfp == NULL))
1294                return;
1295
1296        sdp = sfp->parentdp;
1297        if (unlikely(sdp->detached))
1298                printk(KERN_INFO "sg_rq_end_io: device detached\n");
1299
1300        sense = rq->sense;
1301        result = rq->errors;
1302        resid = rq->resid_len;
1303
1304        SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1305                sdp->disk->disk_name, srp->header.pack_id, result));
1306        srp->header.resid = resid;
1307        ms = jiffies_to_msecs(jiffies);
1308        srp->header.duration = (ms > srp->header.duration) ?
1309                                (ms - srp->header.duration) : 0;
1310        if (0 != result) {
1311                struct scsi_sense_hdr sshdr;
1312
1313                srp->header.status = 0xff & result;
1314                srp->header.masked_status = status_byte(result);
1315                srp->header.msg_status = msg_byte(result);
1316                srp->header.host_status = host_byte(result);
1317                srp->header.driver_status = driver_byte(result);
1318                if ((sdp->sgdebug > 0) &&
1319                    ((CHECK_CONDITION == srp->header.masked_status) ||
1320                     (COMMAND_TERMINATED == srp->header.masked_status)))
1321                        __scsi_print_sense("sg_cmd_done", sense,
1322                                           SCSI_SENSE_BUFFERSIZE);
1323
1324                /* Following if statement is a patch supplied by Eric Youngdale */
1325                if (driver_byte(result) != 0
1326                    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1327                    && !scsi_sense_is_deferred(&sshdr)
1328                    && sshdr.sense_key == UNIT_ATTENTION
1329                    && sdp->device->removable) {
1330                        /* Detected possible disc change. Set the bit - this */
1331                        /* may be used if there are filesystems using this device */
1332                        sdp->device->changed = 1;
1333                }
1334        }
1335        /* Rely on write phase to clean out srp status values, so no "else" */
1336
1337        write_lock_irqsave(&sfp->rq_list_lock, iflags);
1338        if (unlikely(srp->orphan)) {
1339                if (sfp->keep_orphan)
1340                        srp->sg_io_owned = 0;
1341                else
1342                        done = 0;
1343        }
1344        srp->done = done;
1345        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1346
1347        if (likely(done)) {
1348                /* Now wake up any sg_read() that is waiting for this
1349                 * packet.
1350                 */
1351                wake_up_interruptible(&sfp->read_wait);
1352                kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1353                kref_put(&sfp->f_ref, sg_remove_sfp);
1354        } else {
1355                INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1356                schedule_work(&srp->ew.work);
1357        }
1358}
1359
1360static const struct file_operations sg_fops = {
1361        .owner = THIS_MODULE,
1362        .read = sg_read,
1363        .write = sg_write,
1364        .poll = sg_poll,
1365        .unlocked_ioctl = sg_ioctl,
1366#ifdef CONFIG_COMPAT
1367        .compat_ioctl = sg_compat_ioctl,
1368#endif
1369        .open = sg_open,
1370        .mmap = sg_mmap,
1371        .release = sg_release,
1372        .fasync = sg_fasync,
1373        .llseek = no_llseek,
1374};
1375
1376static struct class *sg_sysfs_class;
1377
1378static int sg_sysfs_valid = 0;
1379
1380static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1381{
1382        struct request_queue *q = scsidp->request_queue;
1383        Sg_device *sdp;
1384        unsigned long iflags;
1385        int error;
1386        u32 k;
1387
1388        sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1389        if (!sdp) {
1390                printk(KERN_WARNING "kmalloc Sg_device failure\n");
1391                return ERR_PTR(-ENOMEM);
1392        }
1393
1394        idr_preload(GFP_KERNEL);
1395        write_lock_irqsave(&sg_index_lock, iflags);
1396
1397        error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1398        if (error < 0) {
1399                if (error == -ENOSPC) {
1400                        sdev_printk(KERN_WARNING, scsidp,
1401                                    "Unable to attach sg device type=%d, minor number exceeds %d\n",
1402                                    scsidp->type, SG_MAX_DEVS - 1);
1403                        error = -ENODEV;
1404                } else {
1405                        printk(KERN_WARNING
1406                               "idr allocation Sg_device failure: %d\n", error);
1407                }
1408                goto out_unlock;
1409        }
1410        k = error;
1411
1412        SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1413        sprintf(disk->disk_name, "sg%d", k);
1414        disk->first_minor = k;
1415        sdp->disk = disk;
1416        sdp->device = scsidp;
1417        INIT_LIST_HEAD(&sdp->sfds);
1418        init_waitqueue_head(&sdp->o_excl_wait);
1419        sdp->sg_tablesize = queue_max_segments(q);
1420        sdp->index = k;
1421        kref_init(&sdp->d_ref);
1422        error = 0;
1423
1424out_unlock:
1425        write_unlock_irqrestore(&sg_index_lock, iflags);
1426        idr_preload_end();
1427
1428        if (error) {
1429                kfree(sdp);
1430                return ERR_PTR(error);
1431        }
1432        return sdp;
1433}
1434
1435static int
1436sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1437{
1438        struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1439        struct gendisk *disk;
1440        Sg_device *sdp = NULL;
1441        struct cdev * cdev = NULL;
1442        int error;
1443        unsigned long iflags;
1444
1445        disk = alloc_disk(1);
1446        if (!disk) {
1447                printk(KERN_WARNING "alloc_disk failed\n");
1448                return -ENOMEM;
1449        }
1450        disk->major = SCSI_GENERIC_MAJOR;
1451
1452        error = -ENOMEM;
1453        cdev = cdev_alloc();
1454        if (!cdev) {
1455                printk(KERN_WARNING "cdev_alloc failed\n");
1456                goto out;
1457        }
1458        cdev->owner = THIS_MODULE;
1459        cdev->ops = &sg_fops;
1460
1461        sdp = sg_alloc(disk, scsidp);
1462        if (IS_ERR(sdp)) {
1463                printk(KERN_WARNING "sg_alloc failed\n");
1464                error = PTR_ERR(sdp);
1465                goto out;
1466        }
1467
1468        error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1469        if (error)
1470                goto cdev_add_err;
1471
1472        sdp->cdev = cdev;
1473        if (sg_sysfs_valid) {
1474                struct device *sg_class_member;
1475
1476                sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1477                                                MKDEV(SCSI_GENERIC_MAJOR,
1478                                                      sdp->index),
1479                                                sdp, "%s", disk->disk_name);
1480                if (IS_ERR(sg_class_member)) {
1481                        printk(KERN_ERR "sg_add: "
1482                               "device_create failed\n");
1483                        error = PTR_ERR(sg_class_member);
1484                        goto cdev_add_err;
1485                }
1486                error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1487                                          &sg_class_member->kobj, "generic");
1488                if (error)
1489                        printk(KERN_ERR "sg_add: unable to make symlink "
1490                                        "'generic' back to sg%d\n", sdp->index);
1491        } else
1492                printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1493
1494        sdev_printk(KERN_NOTICE, scsidp,
1495                    "Attached scsi generic sg%d type %d\n", sdp->index,
1496                    scsidp->type);
1497
1498        dev_set_drvdata(cl_dev, sdp);
1499
1500        return 0;
1501
1502cdev_add_err:
1503        write_lock_irqsave(&sg_index_lock, iflags);
1504        idr_remove(&sg_index_idr, sdp->index);
1505        write_unlock_irqrestore(&sg_index_lock, iflags);
1506        kfree(sdp);
1507
1508out:
1509        put_disk(disk);
1510        if (cdev)
1511                cdev_del(cdev);
1512        return error;
1513}
1514
1515static void sg_device_destroy(struct kref *kref)
1516{
1517        struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1518        unsigned long flags;
1519
1520        /* CAUTION!  Note that the device can still be found via idr_find()
1521         * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1522         * any other cleanup.
1523         */
1524
1525        write_lock_irqsave(&sg_index_lock, flags);
1526        idr_remove(&sg_index_idr, sdp->index);
1527        write_unlock_irqrestore(&sg_index_lock, flags);
1528
1529        SCSI_LOG_TIMEOUT(3,
1530                printk("sg_device_destroy: %s\n",
1531                        sdp->disk->disk_name));
1532
1533        put_disk(sdp->disk);
1534        kfree(sdp);
1535}
1536
1537static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1538{
1539        struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1540        Sg_device *sdp = dev_get_drvdata(cl_dev);
1541        unsigned long iflags;
1542        Sg_fd *sfp;
1543
1544        if (!sdp || sdp->detached)
1545                return;
1546
1547        SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1548
1549        /* Need a write lock to set sdp->detached. */
1550        write_lock_irqsave(&sg_index_lock, iflags);
1551        sdp->detached = 1;
1552        list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1553                wake_up_interruptible(&sfp->read_wait);
1554                kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1555        }
1556        write_unlock_irqrestore(&sg_index_lock, iflags);
1557
1558        sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1559        device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1560        cdev_del(sdp->cdev);
1561        sdp->cdev = NULL;
1562
1563        sg_put_dev(sdp);
1564}
1565
1566module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1567module_param_named(def_reserved_size, def_reserved_size, int,
1568                   S_IRUGO | S_IWUSR);
1569module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1570
1571MODULE_AUTHOR("Douglas Gilbert");
1572MODULE_DESCRIPTION("SCSI generic (sg) driver");
1573MODULE_LICENSE("GPL");
1574MODULE_VERSION(SG_VERSION_STR);
1575MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1576
1577MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1578                "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1579MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1580MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1581
1582static int __init
1583init_sg(void)
1584{
1585        int rc;
1586
1587        if (scatter_elem_sz < PAGE_SIZE) {
1588                scatter_elem_sz = PAGE_SIZE;
1589                scatter_elem_sz_prev = scatter_elem_sz;
1590        }
1591        if (def_reserved_size >= 0)
1592                sg_big_buff = def_reserved_size;
1593        else
1594                def_reserved_size = sg_big_buff;
1595
1596        rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1597                                    SG_MAX_DEVS, "sg");
1598        if (rc)
1599                return rc;
1600        sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1601        if ( IS_ERR(sg_sysfs_class) ) {
1602                rc = PTR_ERR(sg_sysfs_class);
1603                goto err_out;
1604        }
1605        sg_sysfs_valid = 1;
1606        rc = scsi_register_interface(&sg_interface);
1607        if (0 == rc) {
1608#ifdef CONFIG_SCSI_PROC_FS
1609                sg_proc_init();
1610#endif                          /* CONFIG_SCSI_PROC_FS */
1611                return 0;
1612        }
1613        class_destroy(sg_sysfs_class);
1614err_out:
1615        unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1616        return rc;
1617}
1618
1619static void __exit
1620exit_sg(void)
1621{
1622#ifdef CONFIG_SCSI_PROC_FS
1623        sg_proc_cleanup();
1624#endif                          /* CONFIG_SCSI_PROC_FS */
1625        scsi_unregister_interface(&sg_interface);
1626        class_destroy(sg_sysfs_class);
1627        sg_sysfs_valid = 0;
1628        unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1629                                 SG_MAX_DEVS);
1630        idr_destroy(&sg_index_idr);
1631}
1632
1633static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1634{
1635        int res;
1636        struct request *rq;
1637        Sg_fd *sfp = srp->parentfp;
1638        sg_io_hdr_t *hp = &srp->header;
1639        int dxfer_len = (int) hp->dxfer_len;
1640        int dxfer_dir = hp->dxfer_direction;
1641        unsigned int iov_count = hp->iovec_count;
1642        Sg_scatter_hold *req_schp = &srp->data;
1643        Sg_scatter_hold *rsv_schp = &sfp->reserve;
1644        struct request_queue *q = sfp->parentdp->device->request_queue;
1645        struct rq_map_data *md, map_data;
1646        int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1647
1648        SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1649                                   dxfer_len));
1650
1651        rq = blk_get_request(q, rw, GFP_ATOMIC);
1652        if (!rq)
1653                return -ENOMEM;
1654
1655        memcpy(rq->cmd, cmd, hp->cmd_len);
1656
1657        rq->cmd_len = hp->cmd_len;
1658        rq->cmd_type = REQ_TYPE_BLOCK_PC;
1659
1660        srp->rq = rq;
1661        rq->end_io_data = srp;
1662        rq->sense = srp->sense_b;
1663        rq->retries = SG_DEFAULT_RETRIES;
1664
1665        if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1666                return 0;
1667
1668        if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1669            dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1670            !sfp->parentdp->device->host->unchecked_isa_dma &&
1671            blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1672                md = NULL;
1673        else
1674                md = &map_data;
1675
1676        if (md) {
1677                if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1678                        sg_link_reserve(sfp, srp, dxfer_len);
1679                else {
1680                        res = sg_build_indirect(req_schp, sfp, dxfer_len);
1681                        if (res)
1682                                return res;
1683                }
1684
1685                md->pages = req_schp->pages;
1686                md->page_order = req_schp->page_order;
1687                md->nr_entries = req_schp->k_use_sg;
1688                md->offset = 0;
1689                md->null_mapped = hp->dxferp ? 0 : 1;
1690                if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1691                        md->from_user = 1;
1692                else
1693                        md->from_user = 0;
1694        }
1695
1696        if (iov_count) {
1697                int len, size = sizeof(struct sg_iovec) * iov_count;
1698                struct iovec *iov;
1699
1700                iov = memdup_user(hp->dxferp, size);
1701                if (IS_ERR(iov))
1702                        return PTR_ERR(iov);
1703
1704                len = iov_length(iov, iov_count);
1705                if (hp->dxfer_len < len) {
1706                        iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1707                        len = hp->dxfer_len;
1708                }
1709
1710                res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1711                                          iov_count,
1712                                          len, GFP_ATOMIC);
1713                kfree(iov);
1714        } else
1715                res = blk_rq_map_user(q, rq, md, hp->dxferp,
1716                                      hp->dxfer_len, GFP_ATOMIC);
1717
1718        if (!res) {
1719                srp->bio = rq->bio;
1720
1721                if (!md) {
1722                        req_schp->dio_in_use = 1;
1723                        hp->info |= SG_INFO_DIRECT_IO;
1724                }
1725        }
1726        return res;
1727}
1728
1729static int sg_finish_rem_req(Sg_request * srp)
1730{
1731        int ret = 0;
1732
1733        Sg_fd *sfp = srp->parentfp;
1734        Sg_scatter_hold *req_schp = &srp->data;
1735
1736        SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1737        if (srp->rq) {
1738                if (srp->bio)
1739                        ret = blk_rq_unmap_user(srp->bio);
1740
1741                blk_put_request(srp->rq);
1742        }
1743
1744        if (srp->res_used)
1745                sg_unlink_reserve(sfp, srp);
1746        else
1747                sg_remove_scat(req_schp);
1748
1749        sg_remove_request(sfp, srp);
1750
1751        return ret;
1752}
1753
1754static int
1755sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1756{
1757        int sg_bufflen = tablesize * sizeof(struct page *);
1758        gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1759
1760        schp->pages = kzalloc(sg_bufflen, gfp_flags);
1761        if (!schp->pages)
1762                return -ENOMEM;
1763        schp->sglist_len = sg_bufflen;
1764        return tablesize;       /* number of scat_gath elements allocated */
1765}
1766
1767static int
1768sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1769{
1770        int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1771        int sg_tablesize = sfp->parentdp->sg_tablesize;
1772        int blk_size = buff_size, order;
1773        gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1774
1775        if (blk_size < 0)
1776                return -EFAULT;
1777        if (0 == blk_size)
1778                ++blk_size;     /* don't know why */
1779        /* round request up to next highest SG_SECTOR_SZ byte boundary */
1780        blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1781        SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1782                                   buff_size, blk_size));
1783
1784        /* N.B. ret_sz carried into this block ... */
1785        mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1786        if (mx_sc_elems < 0)
1787                return mx_sc_elems;     /* most likely -ENOMEM */
1788
1789        num = scatter_elem_sz;
1790        if (unlikely(num != scatter_elem_sz_prev)) {
1791                if (num < PAGE_SIZE) {
1792                        scatter_elem_sz = PAGE_SIZE;
1793                        scatter_elem_sz_prev = PAGE_SIZE;
1794                } else
1795                        scatter_elem_sz_prev = num;
1796        }
1797
1798        if (sfp->low_dma)
1799                gfp_mask |= GFP_DMA;
1800
1801        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1802                gfp_mask |= __GFP_ZERO;
1803
1804        order = get_order(num);
1805retry:
1806        ret_sz = 1 << (PAGE_SHIFT + order);
1807
1808        for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1809             k++, rem_sz -= ret_sz) {
1810
1811                num = (rem_sz > scatter_elem_sz_prev) ?
1812                        scatter_elem_sz_prev : rem_sz;
1813
1814                schp->pages[k] = alloc_pages(gfp_mask, order);
1815                if (!schp->pages[k])
1816                        goto out;
1817
1818                if (num == scatter_elem_sz_prev) {
1819                        if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1820                                scatter_elem_sz = ret_sz;
1821                                scatter_elem_sz_prev = ret_sz;
1822                        }
1823                }
1824
1825                SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1826                                 "ret_sz=%d\n", k, num, ret_sz));
1827        }               /* end of for loop */
1828
1829        schp->page_order = order;
1830        schp->k_use_sg = k;
1831        SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1832                         "rem_sz=%d\n", k, rem_sz));
1833
1834        schp->bufflen = blk_size;
1835        if (rem_sz > 0) /* must have failed */
1836                return -ENOMEM;
1837        return 0;
1838out:
1839        for (i = 0; i < k; i++)
1840                __free_pages(schp->pages[i], order);
1841
1842        if (--order >= 0)
1843                goto retry;
1844
1845        return -ENOMEM;
1846}
1847
1848static void
1849sg_remove_scat(Sg_scatter_hold * schp)
1850{
1851        SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1852        if (schp->pages && schp->sglist_len > 0) {
1853                if (!schp->dio_in_use) {
1854                        int k;
1855
1856                        for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1857                                SCSI_LOG_TIMEOUT(5, printk(
1858                                    "sg_remove_scat: k=%d, pg=0x%p\n",
1859                                    k, schp->pages[k]));
1860                                __free_pages(schp->pages[k], schp->page_order);
1861                        }
1862
1863                        kfree(schp->pages);
1864                }
1865        }
1866        memset(schp, 0, sizeof (*schp));
1867}
1868
1869static int
1870sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1871{
1872        Sg_scatter_hold *schp = &srp->data;
1873        int k, num;
1874
1875        SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1876                                   num_read_xfer));
1877        if ((!outp) || (num_read_xfer <= 0))
1878                return 0;
1879
1880        num = 1 << (PAGE_SHIFT + schp->page_order);
1881        for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1882                if (num > num_read_xfer) {
1883                        if (__copy_to_user(outp, page_address(schp->pages[k]),
1884                                           num_read_xfer))
1885                                return -EFAULT;
1886                        break;
1887                } else {
1888                        if (__copy_to_user(outp, page_address(schp->pages[k]),
1889                                           num))
1890                                return -EFAULT;
1891                        num_read_xfer -= num;
1892                        if (num_read_xfer <= 0)
1893                                break;
1894                        outp += num;
1895                }
1896        }
1897
1898        return 0;
1899}
1900
1901static void
1902sg_build_reserve(Sg_fd * sfp, int req_size)
1903{
1904        Sg_scatter_hold *schp = &sfp->reserve;
1905
1906        SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1907        do {
1908                if (req_size < PAGE_SIZE)
1909                        req_size = PAGE_SIZE;
1910                if (0 == sg_build_indirect(schp, sfp, req_size))
1911                        return;
1912                else
1913                        sg_remove_scat(schp);
1914                req_size >>= 1; /* divide by 2 */
1915        } while (req_size > (PAGE_SIZE / 2));
1916}
1917
1918static void
1919sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1920{
1921        Sg_scatter_hold *req_schp = &srp->data;
1922        Sg_scatter_hold *rsv_schp = &sfp->reserve;
1923        int k, num, rem;
1924
1925        srp->res_used = 1;
1926        SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1927        rem = size;
1928
1929        num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1930        for (k = 0; k < rsv_schp->k_use_sg; k++) {
1931                if (rem <= num) {
1932                        req_schp->k_use_sg = k + 1;
1933                        req_schp->sglist_len = rsv_schp->sglist_len;
1934                        req_schp->pages = rsv_schp->pages;
1935
1936                        req_schp->bufflen = size;
1937                        req_schp->page_order = rsv_schp->page_order;
1938                        break;
1939                } else
1940                        rem -= num;
1941        }
1942
1943        if (k >= rsv_schp->k_use_sg)
1944                SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1945}
1946
1947static void
1948sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1949{
1950        Sg_scatter_hold *req_schp = &srp->data;
1951
1952        SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1953                                   (int) req_schp->k_use_sg));
1954        req_schp->k_use_sg = 0;
1955        req_schp->bufflen = 0;
1956        req_schp->pages = NULL;
1957        req_schp->page_order = 0;
1958        req_schp->sglist_len = 0;
1959        sfp->save_scat_len = 0;
1960        srp->res_used = 0;
1961}
1962
1963static Sg_request *
1964sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1965{
1966        Sg_request *resp;
1967        unsigned long iflags;
1968
1969        write_lock_irqsave(&sfp->rq_list_lock, iflags);
1970        for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1971                /* look for requests that are ready + not SG_IO owned */
1972                if ((1 == resp->done) && (!resp->sg_io_owned) &&
1973                    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1974                        resp->done = 2; /* guard against other readers */
1975                        break;
1976                }
1977        }
1978        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1979        return resp;
1980}
1981
1982/* always adds to end of list */
1983static Sg_request *
1984sg_add_request(Sg_fd * sfp)
1985{
1986        int k;
1987        unsigned long iflags;
1988        Sg_request *resp;
1989        Sg_request *rp = sfp->req_arr;
1990
1991        write_lock_irqsave(&sfp->rq_list_lock, iflags);
1992        resp = sfp->headrp;
1993        if (!resp) {
1994                memset(rp, 0, sizeof (Sg_request));
1995                rp->parentfp = sfp;
1996                resp = rp;
1997                sfp->headrp = resp;
1998        } else {
1999                if (0 == sfp->cmd_q)
2000                        resp = NULL;    /* command queuing disallowed */
2001                else {
2002                        for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2003                                if (!rp->parentfp)
2004                                        break;
2005                        }
2006                        if (k < SG_MAX_QUEUE) {
2007                                memset(rp, 0, sizeof (Sg_request));
2008                                rp->parentfp = sfp;
2009                                while (resp->nextrp)
2010                                        resp = resp->nextrp;
2011                                resp->nextrp = rp;
2012                                resp = rp;
2013                        } else
2014                                resp = NULL;
2015                }
2016        }
2017        if (resp) {
2018                resp->nextrp = NULL;
2019                resp->header.duration = jiffies_to_msecs(jiffies);
2020        }
2021        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2022        return resp;
2023}
2024
2025/* Return of 1 for found; 0 for not found */
2026static int
2027sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2028{
2029        Sg_request *prev_rp;
2030        Sg_request *rp;
2031        unsigned long iflags;
2032        int res = 0;
2033
2034        if ((!sfp) || (!srp) || (!sfp->headrp))
2035                return res;
2036        write_lock_irqsave(&sfp->rq_list_lock, iflags);
2037        prev_rp = sfp->headrp;
2038        if (srp == prev_rp) {
2039                sfp->headrp = prev_rp->nextrp;
2040                prev_rp->parentfp = NULL;
2041                res = 1;
2042        } else {
2043                while ((rp = prev_rp->nextrp)) {
2044                        if (srp == rp) {
2045                                prev_rp->nextrp = rp->nextrp;
2046                                rp->parentfp = NULL;
2047                                res = 1;
2048                                break;
2049                        }
2050                        prev_rp = rp;
2051                }
2052        }
2053        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2054        return res;
2055}
2056
2057static Sg_fd *
2058sg_add_sfp(Sg_device * sdp, int dev)
2059{
2060        Sg_fd *sfp;
2061        unsigned long iflags;
2062        int bufflen;
2063
2064        sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2065        if (!sfp)
2066                return NULL;
2067
2068        init_waitqueue_head(&sfp->read_wait);
2069        rwlock_init(&sfp->rq_list_lock);
2070
2071        kref_init(&sfp->f_ref);
2072        sfp->timeout = SG_DEFAULT_TIMEOUT;
2073        sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2074        sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2075        sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2076            sdp->device->host->unchecked_isa_dma : 1;
2077        sfp->cmd_q = SG_DEF_COMMAND_Q;
2078        sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2079        sfp->parentdp = sdp;
2080        write_lock_irqsave(&sg_index_lock, iflags);
2081        list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2082        write_unlock_irqrestore(&sg_index_lock, iflags);
2083        SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2084        if (unlikely(sg_big_buff != def_reserved_size))
2085                sg_big_buff = def_reserved_size;
2086
2087        bufflen = min_t(int, sg_big_buff,
2088                        queue_max_sectors(sdp->device->request_queue) * 512);
2089        sg_build_reserve(sfp, bufflen);
2090        SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2091                           sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2092
2093        kref_get(&sdp->d_ref);
2094        __module_get(THIS_MODULE);
2095        return sfp;
2096}
2097
2098static void sg_remove_sfp_usercontext(struct work_struct *work)
2099{
2100        struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2101        struct sg_device *sdp = sfp->parentdp;
2102
2103        /* Cleanup any responses which were never read(). */
2104        while (sfp->headrp)
2105                sg_finish_rem_req(sfp->headrp);
2106
2107        if (sfp->reserve.bufflen > 0) {
2108                SCSI_LOG_TIMEOUT(6,
2109                        printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2110                                (int) sfp->reserve.bufflen,
2111                                (int) sfp->reserve.k_use_sg));
2112                sg_remove_scat(&sfp->reserve);
2113        }
2114
2115        SCSI_LOG_TIMEOUT(6,
2116                printk("sg_remove_sfp: %s, sfp=0x%p\n",
2117                        sdp->disk->disk_name,
2118                        sfp));
2119        kfree(sfp);
2120
2121        scsi_device_put(sdp->device);
2122        sg_put_dev(sdp);
2123        module_put(THIS_MODULE);
2124}
2125
2126static void sg_remove_sfp(struct kref *kref)
2127{
2128        struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2129        struct sg_device *sdp = sfp->parentdp;
2130        unsigned long iflags;
2131
2132        write_lock_irqsave(&sg_index_lock, iflags);
2133        list_del(&sfp->sfd_siblings);
2134        write_unlock_irqrestore(&sg_index_lock, iflags);
2135        wake_up_interruptible(&sdp->o_excl_wait);
2136
2137        INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2138        schedule_work(&sfp->ew.work);
2139}
2140
2141static int
2142sg_res_in_use(Sg_fd * sfp)
2143{
2144        const Sg_request *srp;
2145        unsigned long iflags;
2146
2147        read_lock_irqsave(&sfp->rq_list_lock, iflags);
2148        for (srp = sfp->headrp; srp; srp = srp->nextrp)
2149                if (srp->res_used)
2150                        break;
2151        read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2152        return srp ? 1 : 0;
2153}
2154
2155#ifdef CONFIG_SCSI_PROC_FS
2156static int
2157sg_idr_max_id(int id, void *p, void *data)
2158{
2159        int *k = data;
2160
2161        if (*k < id)
2162                *k = id;
2163
2164        return 0;
2165}
2166
2167static int
2168sg_last_dev(void)
2169{
2170        int k = -1;
2171        unsigned long iflags;
2172
2173        read_lock_irqsave(&sg_index_lock, iflags);
2174        idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2175        read_unlock_irqrestore(&sg_index_lock, iflags);
2176        return k + 1;           /* origin 1 */
2177}
2178#endif
2179
2180/* must be called with sg_index_lock held */
2181static Sg_device *sg_lookup_dev(int dev)
2182{
2183        return idr_find(&sg_index_idr, dev);
2184}
2185
2186static Sg_device *sg_get_dev(int dev)
2187{
2188        struct sg_device *sdp;
2189        unsigned long flags;
2190
2191        read_lock_irqsave(&sg_index_lock, flags);
2192        sdp = sg_lookup_dev(dev);
2193        if (!sdp)
2194                sdp = ERR_PTR(-ENXIO);
2195        else if (sdp->detached) {
2196                /* If sdp->detached, then the refcount may already be 0, in
2197                 * which case it would be a bug to do kref_get().
2198                 */
2199                sdp = ERR_PTR(-ENODEV);
2200        } else
2201                kref_get(&sdp->d_ref);
2202        read_unlock_irqrestore(&sg_index_lock, flags);
2203
2204        return sdp;
2205}
2206
2207static void sg_put_dev(struct sg_device *sdp)
2208{
2209        kref_put(&sdp->d_ref, sg_device_destroy);
2210}
2211
2212#ifdef CONFIG_SCSI_PROC_FS
2213
2214static struct proc_dir_entry *sg_proc_sgp = NULL;
2215
2216static char sg_proc_sg_dirname[] = "scsi/sg";
2217
2218static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2219
2220static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2221static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2222                                  size_t count, loff_t *off);
2223static const struct file_operations adio_fops = {
2224        .owner = THIS_MODULE,
2225        .open = sg_proc_single_open_adio,
2226        .read = seq_read,
2227        .llseek = seq_lseek,
2228        .write = sg_proc_write_adio,
2229        .release = single_release,
2230};
2231
2232static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2233static ssize_t sg_proc_write_dressz(struct file *filp, 
2234                const char __user *buffer, size_t count, loff_t *off);
2235static const struct file_operations dressz_fops = {
2236        .owner = THIS_MODULE,
2237        .open = sg_proc_single_open_dressz,
2238        .read = seq_read,
2239        .llseek = seq_lseek,
2240        .write = sg_proc_write_dressz,
2241        .release = single_release,
2242};
2243
2244static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2245static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2246static const struct file_operations version_fops = {
2247        .owner = THIS_MODULE,
2248        .open = sg_proc_single_open_version,
2249        .read = seq_read,
2250        .llseek = seq_lseek,
2251        .release = single_release,
2252};
2253
2254static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2255static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2256static const struct file_operations devhdr_fops = {
2257        .owner = THIS_MODULE,
2258        .open = sg_proc_single_open_devhdr,
2259        .read = seq_read,
2260        .llseek = seq_lseek,
2261        .release = single_release,
2262};
2263
2264static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2265static int sg_proc_open_dev(struct inode *inode, struct file *file);
2266static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2267static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2268static void dev_seq_stop(struct seq_file *s, void *v);
2269static const struct file_operations dev_fops = {
2270        .owner = THIS_MODULE,
2271        .open = sg_proc_open_dev,
2272        .read = seq_read,
2273        .llseek = seq_lseek,
2274        .release = seq_release,
2275};
2276static const struct seq_operations dev_seq_ops = {
2277        .start = dev_seq_start,
2278        .next  = dev_seq_next,
2279        .stop  = dev_seq_stop,
2280        .show  = sg_proc_seq_show_dev,
2281};
2282
2283static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2284static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2285static const struct file_operations devstrs_fops = {
2286        .owner = THIS_MODULE,
2287        .open = sg_proc_open_devstrs,
2288        .read = seq_read,
2289        .llseek = seq_lseek,
2290        .release = seq_release,
2291};
2292static const struct seq_operations devstrs_seq_ops = {
2293        .start = dev_seq_start,
2294        .next  = dev_seq_next,
2295        .stop  = dev_seq_stop,
2296        .show  = sg_proc_seq_show_devstrs,
2297};
2298
2299static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2300static int sg_proc_open_debug(struct inode *inode, struct file *file);
2301static const struct file_operations debug_fops = {
2302        .owner = THIS_MODULE,
2303        .open = sg_proc_open_debug,
2304        .read = seq_read,
2305        .llseek = seq_lseek,
2306        .release = seq_release,
2307};
2308static const struct seq_operations debug_seq_ops = {
2309        .start = dev_seq_start,
2310        .next  = dev_seq_next,
2311        .stop  = dev_seq_stop,
2312        .show  = sg_proc_seq_show_debug,
2313};
2314
2315
2316struct sg_proc_leaf {
2317        const char * name;
2318        const struct file_operations * fops;
2319};
2320
2321static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2322        {"allow_dio", &adio_fops},
2323        {"debug", &debug_fops},
2324        {"def_reserved_size", &dressz_fops},
2325        {"device_hdr", &devhdr_fops},
2326        {"devices", &dev_fops},
2327        {"device_strs", &devstrs_fops},
2328        {"version", &version_fops}
2329};
2330
2331static int
2332sg_proc_init(void)
2333{
2334        int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2335        int k;
2336
2337        sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2338        if (!sg_proc_sgp)
2339                return 1;
2340        for (k = 0; k < num_leaves; ++k) {
2341                const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2342                umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2343                proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2344        }
2345        return 0;
2346}
2347
2348static void
2349sg_proc_cleanup(void)
2350{
2351        int k;
2352        int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2353
2354        if (!sg_proc_sgp)
2355                return;
2356        for (k = 0; k < num_leaves; ++k)
2357                remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2358        remove_proc_entry(sg_proc_sg_dirname, NULL);
2359}
2360
2361
2362static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2363{
2364        seq_printf(s, "%d\n", *((int *)s->private));
2365        return 0;
2366}
2367
2368static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2369{
2370        return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2371}
2372
2373static ssize_t 
2374sg_proc_write_adio(struct file *filp, const char __user *buffer,
2375                   size_t count, loff_t *off)
2376{
2377        int err;
2378        unsigned long num;
2379
2380        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2381                return -EACCES;
2382        err = kstrtoul_from_user(buffer, count, 0, &num);
2383        if (err)
2384                return err;
2385        sg_allow_dio = num ? 1 : 0;
2386        return count;
2387}
2388
2389static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2390{
2391        return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2392}
2393
2394static ssize_t 
2395sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2396                     size_t count, loff_t *off)
2397{
2398        int err;
2399        unsigned long k = ULONG_MAX;
2400
2401        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2402                return -EACCES;
2403
2404        err = kstrtoul_from_user(buffer, count, 0, &k);
2405        if (err)
2406                return err;
2407        if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2408                sg_big_buff = k;
2409                return count;
2410        }
2411        return -ERANGE;
2412}
2413
2414static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2415{
2416        seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2417                   sg_version_date);
2418        return 0;
2419}
2420
2421static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2422{
2423        return single_open(file, sg_proc_seq_show_version, NULL);
2424}
2425
2426static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2427{
2428        seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2429                   "online\n");
2430        return 0;
2431}
2432
2433static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2434{
2435        return single_open(file, sg_proc_seq_show_devhdr, NULL);
2436}
2437
2438struct sg_proc_deviter {
2439        loff_t  index;
2440        size_t  max;
2441};
2442
2443static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2444{
2445        struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2446
2447        s->private = it;
2448        if (! it)
2449                return NULL;
2450
2451        it->index = *pos;
2452        it->max = sg_last_dev();
2453        if (it->index >= it->max)
2454                return NULL;
2455        return it;
2456}
2457
2458static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2459{
2460        struct sg_proc_deviter * it = s->private;
2461
2462        *pos = ++it->index;
2463        return (it->index < it->max) ? it : NULL;
2464}
2465
2466static void dev_seq_stop(struct seq_file *s, void *v)
2467{
2468        kfree(s->private);
2469}
2470
2471static int sg_proc_open_dev(struct inode *inode, struct file *file)
2472{
2473        return seq_open(file, &dev_seq_ops);
2474}
2475
2476static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2477{
2478        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2479        Sg_device *sdp;
2480        struct scsi_device *scsidp;
2481        unsigned long iflags;
2482
2483        read_lock_irqsave(&sg_index_lock, iflags);
2484        sdp = it ? sg_lookup_dev(it->index) : NULL;
2485        if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2486                seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2487                              scsidp->host->host_no, scsidp->channel,
2488                              scsidp->id, scsidp->lun, (int) scsidp->type,
2489                              1,
2490                              (int) scsidp->queue_depth,
2491                              (int) scsidp->device_busy,
2492                              (int) scsi_device_online(scsidp));
2493        else
2494                seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2495        read_unlock_irqrestore(&sg_index_lock, iflags);
2496        return 0;
2497}
2498
2499static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2500{
2501        return seq_open(file, &devstrs_seq_ops);
2502}
2503
2504static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2505{
2506        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2507        Sg_device *sdp;
2508        struct scsi_device *scsidp;
2509        unsigned long iflags;
2510
2511        read_lock_irqsave(&sg_index_lock, iflags);
2512        sdp = it ? sg_lookup_dev(it->index) : NULL;
2513        if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2514                seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2515                           scsidp->vendor, scsidp->model, scsidp->rev);
2516        else
2517                seq_printf(s, "<no active device>\n");
2518        read_unlock_irqrestore(&sg_index_lock, iflags);
2519        return 0;
2520}
2521
2522/* must be called while holding sg_index_lock */
2523static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2524{
2525        int k, m, new_interface, blen, usg;
2526        Sg_request *srp;
2527        Sg_fd *fp;
2528        const sg_io_hdr_t *hp;
2529        const char * cp;
2530        unsigned int ms;
2531
2532        k = 0;
2533        list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2534                k++;
2535                read_lock(&fp->rq_list_lock); /* irqs already disabled */
2536                seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2537                           "(res)sgat=%d low_dma=%d\n", k,
2538                           jiffies_to_msecs(fp->timeout),
2539                           fp->reserve.bufflen,
2540                           (int) fp->reserve.k_use_sg,
2541                           (int) fp->low_dma);
2542                seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2543                           (int) fp->cmd_q, (int) fp->force_packid,
2544                           (int) fp->keep_orphan);
2545                for (m = 0, srp = fp->headrp;
2546                                srp != NULL;
2547                                ++m, srp = srp->nextrp) {
2548                        hp = &srp->header;
2549                        new_interface = (hp->interface_id == '\0') ? 0 : 1;
2550                        if (srp->res_used) {
2551                                if (new_interface && 
2552                                    (SG_FLAG_MMAP_IO & hp->flags))
2553                                        cp = "     mmap>> ";
2554                                else
2555                                        cp = "     rb>> ";
2556                        } else {
2557                                if (SG_INFO_DIRECT_IO_MASK & hp->info)
2558                                        cp = "     dio>> ";
2559                                else
2560                                        cp = "     ";
2561                        }
2562                        seq_printf(s, cp);
2563                        blen = srp->data.bufflen;
2564                        usg = srp->data.k_use_sg;
2565                        seq_printf(s, srp->done ? 
2566                                   ((1 == srp->done) ?  "rcv:" : "fin:")
2567                                   : "act:");
2568                        seq_printf(s, " id=%d blen=%d",
2569                                   srp->header.pack_id, blen);
2570                        if (srp->done)
2571                                seq_printf(s, " dur=%d", hp->duration);
2572                        else {
2573                                ms = jiffies_to_msecs(jiffies);
2574                                seq_printf(s, " t_o/elap=%d/%d",
2575                                        (new_interface ? hp->timeout :
2576                                                  jiffies_to_msecs(fp->timeout)),
2577                                        (ms > hp->duration ? ms - hp->duration : 0));
2578                        }
2579                        seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2580                                   (int) srp->data.cmd_opcode);
2581                }
2582                if (0 == m)
2583                        seq_printf(s, "     No requests active\n");
2584                read_unlock(&fp->rq_list_lock);
2585        }
2586}
2587
2588static int sg_proc_open_debug(struct inode *inode, struct file *file)
2589{
2590        return seq_open(file, &debug_seq_ops);
2591}
2592
2593static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2594{
2595        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2596        Sg_device *sdp;
2597        unsigned long iflags;
2598
2599        if (it && (0 == it->index)) {
2600                seq_printf(s, "max_active_device=%d(origin 1)\n",
2601                           (int)it->max);
2602                seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2603        }
2604
2605        read_lock_irqsave(&sg_index_lock, iflags);
2606        sdp = it ? sg_lookup_dev(it->index) : NULL;
2607        if (sdp && !list_empty(&sdp->sfds)) {
2608                struct scsi_device *scsidp = sdp->device;
2609
2610                seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2611                if (sdp->detached)
2612                        seq_printf(s, "detached pending close ");
2613                else
2614                        seq_printf
2615                            (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2616                             scsidp->host->host_no,
2617                             scsidp->channel, scsidp->id,
2618                             scsidp->lun,
2619                             scsidp->host->hostt->emulated);
2620                seq_printf(s, " sg_tablesize=%d excl=%d\n",
2621                           sdp->sg_tablesize, get_exclude(sdp));
2622                sg_proc_debug_helper(s, sdp);
2623        }
2624        read_unlock_irqrestore(&sg_index_lock, iflags);
2625        return 0;
2626}
2627
2628#endif                          /* CONFIG_SCSI_PROC_FS */
2629
2630module_init(init_sg);
2631module_exit(exit_sg);
2632
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