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